Build a calculator
for your website
Describe the calculator you need, edit any part of it, then paste the embed code on your site.
Free, and no sign-up needed.
Examples
Three calculators published from this page: a quote calculator for a patio business, a freelance day rate tool with its own dark theme, and a solar savings estimator that answers in words as well as numbers.
How it works
Describe it
Type what you need and a working calculator appears in seconds.
Make it yours
Click any part to edit it, add fields, or change the colours and layout.
Paste it on your site
Copy two short lines to embed the calculator on your website, on any platform.
What you can build
Anything that takes a few inputs and works out a result. Quote and price calculators, converters, loan and mortgage tools, health and fitness measures, ROI and savings estimates. Results can be numbers or words, such as a category or a band.
What it adds to your page
A published calculator is two files, about 7 KB in total: a small script holding your calculator, and a shared renderer. Nothing else loads, and no advertising or analytics scripts run on your page. Several calculators on one page share the renderer, so each additional one costs about 1 KB.
We measured the embeds of five other calculator builders in September 2026. They ranged from about 80 KB to about 4 MB. Most load a JavaScript framework and fetch the calculator definition from the vendor before it appears.
The calculator is a static file served from a CDN. It renders inside a Shadow DOM, so your site’s CSS cannot affect the calculator and the calculator’s CSS cannot leak into your site. Formulas are compiled to bytecode when you publish, and the runtime executes those instructions directly. It does not use eval, so a calculator definition cannot execute as code. Results are worked out in the browser, with no request to our servers.
Common questions
Is it free?
It is currently free to use with no sign-up. We may introduce paid plans or limits in future, and will give notice before any change.
Do I need to know how to code?
No. This is a no-code calculator builder: describe what you need, or build it by clicking, then copy and paste the result.
Where can I put the calculator?
Anywhere you can paste a snippet of code. That covers WordPress, Shopify, Squarespace, Wix, Webflow and plain HTML pages, along with most other site builders.
Can I make a custom calculator for my website?
Yes. Everything here is a custom calculator: your fields, your formulas, your colours and fonts. The result is a small widget that matches your site rather than a generic embed.
How do I embed the calculator on my website?
Publishing gives you a two-line embed code: a div and a script tag. Paste it where you want the calculator to appear. The files are served from our CDN, so there is nothing to install or maintain.
Will it slow my page down?
A calculator adds two requests and roughly 7 KB. Several calculators on the same page share one renderer, so each additional one costs about 1 KB.
Can I edit a calculator after publishing it?
Yes. Because there is no account, the key to your calculator is kept in the browser you built it in, so open the builder there and it is ready to edit. A published calculator keeps working on your site either way, and you can publish a fresh one at any time.
What happens to the numbers people type in?
They stay in the visitor’s browser. The calculation runs there and the figures are not sent to us.
Will it keep working later?
Once added to your site, a calculator is designed to keep running there, subject to our terms of use.