Free calculators and tools for A/B tests, ad spend, pricing and AI visibility

Conversion rate from conversions and visitors, or orders and sessions, plus how many conversions a target rate needs.

Answers: What is my conversion rate, and how many conversions would a target rate need?

Use it: Before anything else: to find your baseline, compare two periods or set a goal.

How many visitors each variant needs, and how many days to run, from your baseline rate and the smallest lift worth detecting.

Answers: How many visitors does each variant need, and how many days will the test take?

Use it: Before a test starts, so you know whether your traffic can detect the change you care about.

A two-proportion z-test for a finished A/B test: the p-value, the lift and a confidence interval for the difference.

Answers: Is the difference between control and variant bigger than chance would explain?

Use it: Once a test reaches its planned sample size, not before.

The p-value of a z, t or chi-square statistic, left-tailed, right-tailed or two-tailed, with the critical value and the decision at your significance level.

Answers: What is the p-value of my z, t or chi-square statistic, and do I reject the null hypothesis?

Use it: When you already have a test statistic, from software, a paper or a textbook formula, and need its p-value or critical value.

Three calculators: the confidence interval for a mean (t or z), the Wilson interval for a proportion such as a conversion rate, and the margin of error of a survey percentage.

Answers: How precisely does my sample pin down a mean, a conversion rate or a survey percentage?

Use it: When you report a number measured on a sample and want the range the true figure plausibly lies in.

Three calculators: the margin of error of a percentage, the margin of error of a mean (t or z), and the sample size for a target margin, each with the finite population correction.

Answers: How far off could a survey result, a poll or a conversion rate be, and how many responses do I need?

Use it: When you report a percentage or an average from a sample, or plan a survey to a set precision.

The score from -100 to 100 and the share of each group, with the margin of error for your sample size, a confidence interval, and a test of whether the gap between two surveys is larger than the noise.

Answers: What is my Net Promoter Score, how precise is it, and did it really change since the last survey?

Use it: When you report an NPS from a survey, or compare this period's score with the last one.

Chi-square test of independence and goodness of fit with expected counts, degrees of freedom, p-value, critical value, Cramér's V, a small-count warning and Yates's correction on 2 by 2 tables.

Answers: Are two categorical variables related, or do my counts match the shares I expected?

Use it: When you compare conversion across three or more variants, check a traffic split, or test any table of counts.

Standard error of the mean from SD and n or raw data, of a proportion and of the difference between two rates, with the steps and the confidence interval each implies.

Answers: How precisely does my sample measure the mean or the rate?

Use it: When you report an average or a conversion rate from a sample, or need the standard error of the difference between two versions.

The CSAT score and the average rating, with the margin of error for your sample size, a Wilson confidence interval, and a test of whether the gap between two surveys is larger than the noise.

Answers: What is my customer satisfaction score, how precise is it, and did it really change since the last survey?

Use it: When you report a CSAT from a survey, or compare this period's score with the last one.

Return on ad spend from ad revenue and ad spend, with ACoS, plus your break-even ROAS from your gross margin.

Answers: How much revenue does each dollar of ad spend bring in, and is that enough to make money?

Use it: When you judge campaigns that report a revenue value, or set a target ROAS.

Break-even ROAS, break-even CPA and a target ROAS built from one order's price and costs, with discounts, refunds and repeat orders, plus a shortcut from your margin.

Answers: What ROAS do my ads need before an order stops losing money, and what is the most I can pay to win one?

Use it: Before you launch or scale a campaign, and again whenever a price, a cost or a discount changes.

CPA from cost and conversions, how cost per click and conversion rate make it up, and your break-even CPA.

Answers: What does each sale, lead or sign-up cost, and what is the most I can afford to pay?

Use it: When you judge campaigns by conversions, such as leads or sign-ups, or set a target CPA.

Cost per click from cost and clicks, or cost or clicks from the other two, plus the break-even CPC your conversion rate lets you afford and the clicks and conversions a budget buys.

Answers: What does each click cost, and what is the most I can afford to pay for one?

Use it: When you judge or plan campaigns bought by the click, or set a maximum CPC bid.

CTR from clicks and impressions with a confidence interval, a significance test for two CTRs, and the path from CTR to cost, conversions and CPA.

Answers: What is my click-through rate, is one ad's CTR really better than another's, and what are the clicks worth?

Use it: When you compare ads, subject lines or search results by clicks, or plan the impressions a click target needs.

CPM, total cost or impressions from the other two, eCPM and RPM from earnings, and a CPM converted to cost per click and cost per acquisition against your break-even CPA.

Answers: What does it cost to be shown a thousand times, and what does that come to per click and per sale?

Use it: When you price or compare media bought per thousand impressions, or want to know what your own ad space earned per thousand.

Builds the tagged URL in your browser, keeps existing query strings and fragments, checks the medium against Google's default channel rules, and tags up to 500 links at once in bulk mode.

Answers: How do I tag a link so analytics knows which ad, email or post sent each visitor?

Use it: Before a campaign goes out, for every link the ad platform does not tag for you.

Character counts against Google's limits, with Chinese, Japanese and Korean characters counted as 2, flags for text Google's editorial policies name, and example combinations at phone and desktop widths. Not affiliated with Google.

Answers: Do my headlines and descriptions fit Google's limits, and how might they read together in the ad?

Use it: Before you add a responsive search ad to Google Ads, or when a client approves ad copy.

ROI and annualized ROI from the amount invested and returned, marketing ROI on gross profit, and what a conversion rate lift is worth on your own traffic, with payback and the break-even lift.

Answers: What did an investment, a campaign or a conversion lift return for what it cost?

Use it: When you judge a finished investment or campaign, or put a value on a lift before you decide what the work is worth.

Profit margin from any two of cost, selling price, profit and margin, with the markup beside it, plus the price for a target margin and gross, operating and net profit margin.

Answers: What is my profit margin, and what price do I need for the margin I want?

Use it: When you price a product, weigh a discount, or need the gross margin that break-even ROAS and CPA are built on.

Markup from any two of cost, selling price, profit and markup percentage, with the matching margin, a selling price with tax as a separate line, a markup to margin converter, and the conversion rate a markup change has to hold.

Answers: What markup am I making, what should I charge for a given markup, and what margin does that leave?

Use it: When you set or check a price from a cost, and before you raise or lower one.

Lifetime value for a store or a subscription, then CAC, the LTV to CAC ratio and the payback period, with the formulas and worked examples.

Answers: What is a customer worth over time, what does one cost to win, and how long until that cost is earned back?

Use it: When you set a limit for acquisition cost, or check whether growth pays for itself.

Gross, operating and net profit from a selling price, a cost and the units sold, or from the totals for a period, each as an amount and as a percentage of revenue, with the profit per unit and the break-even number of units.

Answers: How much profit did I make, on one sale or over a period, after every cost?

Use it: When you close a month, check whether a product pays for its ads and overheads, or want to know how many sales it takes to break even.

Sale price, amount saved, percent off and original price, stacked discounts, and what a discount does to your margin and to the units you need to sell for the same gross profit.

Answers: What is the sale price after a discount, what percent off is this, and how many more sales does a discount need?

Use it: When you price a sale or a coupon, check a deal, or weigh a promotion against your margin.

The break-even point in units and in sales, the contribution margin and its ratio, the margin of safety, the units or the price for a target profit, and the conversion rate and traffic you need to break even.

Answers: How many units, how much revenue and what conversion rate do I need to cover all my costs?

Use it: When you plan a product, a price change or a month's budget, or want to know how far sales can fall before you make a loss.

Fully loaded CAC from six cost lines, with the ad-spend-only figure and paid CAC beside it, then the payback period, the most you can pay for a customer in the time you can wait, and the LTV to CAC ratio from your own lifetime value.

Answers: What does a new customer really cost to win once salaries, fees and tools are counted, and how long until that cost is earned back?

Use it: When you set a marketing budget, check whether a paid channel pays, or need a limit for what a customer can cost.

The fee and the net on a payment, and the amount to request so a set sum is left, from PayPal's published US rates, with the international fee, an estimate of the conversion spread and the fee as a share of gross profit.

Answers: What does PayPal take from a payment, and what do I request to be left with a set amount?

Use it: When you price a product or an invoice that will be paid through PayPal, or work out what payment fees do to your margin.

The Stripe fee and net payout on an amount, the smallest charge that leaves a target sum after the fee, and the fees on a month of payments. Preset with Stripe's published US rates, each one editable and linked to its source.

Answers: What does Stripe keep from a payment, what reaches me, and what should I charge to cover the fee?

Use it: When you price a product or an invoice, or count payment fees as a cost in a margin or an ad target.

The Shopify Payments fee or the third-party transaction fee on a sale and what you net, then a month and a year of fees plus the plan price with every plan side by side, from Shopify's published US rates.

Answers: What does Shopify take from a sale on my plan, what do I net, and which plan costs less for my orders?

Use it: When you choose a Shopify plan or payment provider, or count payment fees as a cost in a price, margin or ad target.

eBay's final value fee on the total amount of the sale, the per order fee and the other fees eBay lists, what you keep, profit and margin after your costs, and the item price that keeps a target, from eBay's published US rates.

Answers: What does eBay take from a sale, what do I keep, and what price keeps the amount I want?

Use it: When you price an item for eBay, check a payout, or work out the profit on a sale after fees, postage and the item cost.

Etsy's transaction, payment processing and listing fees, Offsite Ads with the $100 cap, what you keep, profit and margin, and the price to charge, from Etsy's published US rates, each one editable.

Answers: What does Etsy take from a sale, what do I keep, and what price keeps the amount I want?

Use it: When you price a listing for Etsy or check what a sale leaves you after fees, shipping and the item cost.

Whatnot's commission by category and sales tier on the sale price, payment processing on the buyer's total, the $1,500 high-value rule, what you keep, profit and the price to sell for, from Whatnot's published US rates, each one editable.

Answers: What does Whatnot take from a sale at my tier, what do I keep, and what does an item need to sell for?

Use it: When you set a starting bid or check what a sale on Whatnot leaves you after commission and processing.

The Venmo fee and what you receive on goods and services, a business profile, Tap to Pay or a charity profile, the amount to request so a set sum is left, and the Instant Transfer fee, from Venmo's published US rates.

Answers: What does Venmo take from a payment, what do I receive, and what should I request?

Use it: When a customer pays you on Venmo for goods or services, when you choose between a personal and a business profile, or before you cash out with Instant Transfer.

Square's processing fee and what you receive on a payment, the amount to charge so a set sum is left, and a month of fees on Square Free, Plus and Premium, from Square's published US rates.

Answers: What does Square take from a payment, what do I receive, and which Square plan costs least for my month?

Use it: When you price for card payments in person, online or by invoice, compare Square Free, Plus and Premium, or estimate a month of processing fees.

Commission from a sale amount and a rate, the rate from an amount paid, the sales needed for a target, base pay plus commission, tiered commission read both ways, a two-way split and affiliate commission from clicks.

Answers: What commission does a sale earn, and what does a tiered plan or a split really pay?

Use it: When you check a commission statement, plan a sales target, compare the two readings of a tiered plan, or work out affiliate earnings from clicks.

Enter your website and it grades the page live in eight checks, from first impressions and mobile to speed, SEO fundamentals and AI agent readiness, with a score out of 100 per check, an overall website score and every finding.

Answers: How does my website score, and what should I fix first?

Use it: When you want a quick score for your homepage or main page, before an audit or a redesign, and after each change.

Enter your website and get a blunt review of one page in eight checks, from the first screen and calls to action to trust, mobile, speed and AI agent readiness, with every finding and why it matters.

Answers: What would a blunt reviewer say is costing my website customers?

Use it: When you want an honest outside view of your site before a redesign, a launch or more ad spend.

Enter a URL and it checks the page live in eight areas, from first impressions to AI agent readiness and SEO fundamentals, with a score out of 100 per check and every finding. A self-check version needs no email.

Answers: Which known conversion problems does my landing page have, and what should I fix first?

Use it: Before you test or redesign a landing page, and after each change.

Nine rule-based checks for a landing page headline, a Google search ad headline, a meta title or an email subject line, each marked pass, review or fix, with a score whose math is shown. Includes a headline generator that fills named formulas with your own words.

Answers: Does this headline say what is offered, and does it fit the place it will run?

Use it: Before a landing page, an ad or an email goes live, and when you choose which headlines to test.

Flesch Reading Ease and Flesch-Kincaid Grade Level for any English text, with the word, sentence and syllable counts, the working, your longest sentences and your longest words. The text stays in your browser.

Answers: How hard is this copy to read, and which sentences and words make it hard?

Use it: When you edit landing page, product or email copy, and when you compare a rewrite with the version it replaces.

A six-box canvas for the customer and the offer, a builder that fills a positioning statement, a one-line statement and a landing page hero draft from your own words, and a six-rule check. No AI model, nothing stored.

Answers: Who is this for, what do they get, and why should they choose it over what they use now?

Use it: Before you write or rewrite the first screen of a homepage or landing page, and before you test a new headline.

Reads the theme object a Shopify store's page sends: the theme's schema name and version, any Theme Store ID, and the store's name for its copy. Names apps only from a list of documented script hosts, lists every other script host as found, and says what no detector can see.

Answers: What Shopify theme is this store using, and which apps does its page load?

Use it: When you admire a competitor's store, shortlist themes, or check what a store loads on its storefront.

Names apps from a list of script hosts checked on each vendor's own documentation, lists theme app extension folders, app loader scripts and every other host as found, shows the theme on one line, and says what no detector can see.

Answers: What apps is this Shopify store using?

Use it: When you want to see which apps a competitor's storefront loads, or check what your own store still loads.

Finds the theme folders in a site's page and reads each theme's style.css header: Theme Name, Author, Version and the parent of a child theme. Lists the plugin folders the page loads, named only from a checked list, and says what it cannot see.

Answers: What WordPress theme is that site using, is it a child theme, and which plugins does the page load?

Use it: When you like how a WordPress or WooCommerce site looks, shortlist themes, or check what a site loads.

Reads a page's search and share tags and checks each against Google's, the Open Graph protocol's, LinkedIn's or X's own documentation, with approximate previews of a Google result, a share card and an X card. By address it also reads the share image's size and type. A generator writes the tags from a form.

Answers: What do my title, description, canonical, robots, Open Graph and X tags say, and how might the page look in Google and in a shared link?

Use it: Before a page goes live, after a template change, or when a shared link shows the wrong title or image.

Reads a page's twitter: tags with the Open Graph fallbacks X documents and checks the card type, the tags each card requires, the documented lengths and the image, each against X's own cards documentation. By address it also reads the card image's size and type and whether robots.txt lets Twitterbot in. Built by Convertica, not X.

Answers: Will a link to my page get a card on X, and which tags are missing or out of range?

Use it: Before you share a page on X, after a template change, or when a posted link shows no card or the wrong one.

Lists every icon a site declares, reads each file's real format and pixel size from its bytes, and checks it against Google's favicon rules: square, at least 8 x 8 pixels, a supported format, and crawlable by Googlebot and Googlebot-Image under robots.txt. It cannot say whether Google shows the icon today.

Answers: Does my favicon meet Google's rules, and why is it not showing in search results?

Use it: After you add or change a favicon, or when Google shows a blank globe instead of your icon.

Checks whether http redirects to https and in how many steps, whether a secure connection can be made, the HSTS header, and every http:// script, image, font, form and download in the page, sorted by what Chrome blocks, upgrades or warns on, each rule from MDN, the W3C or the Chromium Blog. It cannot read the certificate.

Answers: Why does Chrome say Not secure on my site, and what do I fix first?

Use it: When Chrome shows Not secure on your site, after moving to https, or after adding a widget, a form or an embed.

Reads a domain's SPF record and counts its DNS lookups through every include, finds DKIM keys at the selectors providers publish, reads the DMARC policy, MX and BIMI, and checks each against the RFCs and Google's and Yahoo's sender requirements. It reads DNS only: it cannot see inbox placement, reputation or content.

Answers: Why are my emails going to spam, and are my SPF, DKIM and DMARC records set up the way Gmail and Yahoo require?

Use it: When order emails, cart reminders or newsletters land in spam, after you add a sending tool, or before a big send.

Scores one page's AI visibility and agent readiness out of 100 alongside seven other checks, and an instant check shows which AI crawlers a robots.txt file allows or blocks. It reads your site only: it does not ask ChatGPT or Google whether they cite you.

Answers: Can AI search engines and AI agents reach my page and read it, and which AI crawlers does my robots.txt let in?

Use it: Before you work on AI search visibility, and after any change to robots.txt, bot protection or how a page is rendered.

An AI agent opens your site in a real browser and tries to reach checkout or your contact form while you watch, then shows each step and what stopped it. It never pays, orders or submits a form, and it is Convertica's own agent, not another company's.

Answers: Can an AI shopping agent find a product on my site, add it to the cart and reach checkout, and where does it get stuck?

Use it: Before you work on agent readiness, and after a change to product pages, the cart, popups or checkout.

Builds an llms.txt file from a short form and checks any file against the format at llmstxt.org, labeling each finding as a format rule or as practical advice. Runs in your browser, with nothing sent anywhere.

Answers: What should my llms.txt file say, and is the one I have valid?

Use it: When you publish or change an llms.txt file, before you call it done.

Builds FAQPage JSON-LD from question and answer pairs you can reorder, flags empty and repeated questions, and escapes the output so that no answer can break the script tag. Explains what the markup does now that Google has retired FAQ rich results. Runs in your browser, with nothing sent anywhere.

Answers: How do I write FAQPage markup that matches my FAQ, and is it still worth adding?

Use it: When a page has a visible FAQ and you want its questions and answers in structured data.

Writes JSON-LD for eight schema.org types from a form with addable rows for profile links, opening hours, offers and breadcrumb steps, and checks it as you type against the properties Google's documentation requires and recommends. Copy or download the block. Runs in your browser, with nothing sent anywhere.

Answers: How do I write JSON-LD for my organization, business, product, article, breadcrumbs, people, site or event?

Use it: When a page has no structured data yet, or the markup it has is missing what Google requires.

Checks pasted JSON-LD against schema.org's vocabulary and Google's published property lists. Reports JSON mistakes with line and column, unknown names, values of the wrong kind and missing properties, each labeled as an error, a Google requirement, a Google recommendation or advice. Runs in your browser, with nothing sent anywhere.

Answers: Is my JSON-LD valid, and does it have what Google asks for?

Use it: When you have written or changed structured data and want it checked before, or after, it goes live.

Reads a page's HTML before any JavaScript runs and reports the title, noindex and canonical signals, words of text, headings, links and JSON-LD types, plus the status, redirects and robots.txt rules when it fetches the page. Paste the rendered DOM as well and it lists the text and links that exist only after JavaScript. It renders nothing and gives no score.

Answers: What does a crawler that runs no JavaScript get from my page, and is anything stopping it?

Use it: When a page is not being indexed or quoted, after a redesign or a move to a JavaScript framework, or before you launch a template.

Fetches one page and its robots.txt and lists what stops Google from indexing it, worst first: the status code, redirects, a robots.txt block for Googlebot, a noindex, a canonical that points elsewhere and content that needs JavaScript. Each check gives the fix and Google's own page for the rule. It does not say whether a page is indexed.

Answers: Why is my website not showing up on Google, and what do I fix?

Use it: When a new or redesigned site, or one page, cannot be found on Google, or after a move from a staging server.

Builds a robots.txt file from a short form, with presets and a setting for each of 20 AI crawlers, then tests the file and shows which crawlers it allows or blocks and which line decides. A tester checks any robots.txt against any crawler and URL. Runs in your browser, with nothing sent anywhere.

Answers: What should my robots.txt say, which AI crawlers will it let in, and does the file I have do what I think?

Use it: When you write or change a robots.txt file, and before you decide what AI crawlers may do on your site.

Writes the GA4 regular expression for a channel group or an exploration, one expression per assistant, the values for a comparison and the same list as a Data Studio formula and a BigQuery condition. A checker labels pasted referrers by assistant. It connects to no account.

Answers: How do I see visits from ChatGPT, Perplexity, Gemini and other AI assistants in Google Analytics 4?

Use it: When you want AI assistants as their own segment, one row per assistant, or the same list in Data Studio or BigQuery.

Two calculators: every brand's share, rank and gap to the leader from plain counts, and AI share of voice from a prompt set, with the mention rate, the share of mentions and a confidence interval. You bring the counts.

Answers: What share of the mentions, impressions or AI answers in my market is mine, and how far ahead is the leader?

Use it: When you compare your brand with named competitors on one metric, or after you have run a set of prompts in AI assistants and counted who was named.