Free calculator widgets for your website
Give your readers a working calculator without building one. Copy the code, paste it into your page, and it works. No ads, no cookies, no sign-up, no fees.
Pick a calculator
Open the calculator and use the Embed this calculator on your site box at the foot of the page. It holds the code and a copy button.
- Mortgage calculator: monthly payment, total interest and an amortization schedule.
- Compound interest calculator: growth of a lump sum and regular contributions, year by year.
- Percentage calculator: percentage of a number, percentage change and more.
- ROI calculator: return on investment and annualized return.
- Tip calculator: the tip, the total and each person's share of the bill.
See one working
This is the percentage calculator, embedded exactly as it would be on your site.
Questions site owners ask
Is the embed code safe to put on my site?
Yes. The calculator runs inside an iframe served from freecalchub.com. The browser keeps it separate from your page, so it cannot read or change your content, your forms or your visitors' details. The code also carries a sandbox attribute that stops the frame from ever redirecting your page. You can read every line of it before you paste it.
Does it track my visitors?
No cookies are set and there is no cookie banner. The only analytics is Plausible, which counts page views without cookies or personal data.
Are there ads in the calculator?
No. There are no ads, no sign-up and no fees inside the frame.
Will it slow down my page?
The frame loads lazily: the browser fetches it only when a visitor scrolls near it, so it does not hold up the rest of your page.
Will it affect my SEO?
The embedded copy tells search engines not to index it, so it never competes with your page. The credit line under the frame is optional: keep it, delete it or mark it nofollow.
How do I know the numbers are right?
Every frame links to the full calculator page, which explains how the answer is worked out, so you and your readers can check it.
Does it work on phones?
Yes. The frame fills the width of your column, up to 720 pixels, and the calculator inside fits itself to that width.
Can I change the size?
Yes. Change the height number in the code if your layout needs more or less room.
Something not working?
Email support@freecalchub.com with the address of the page it is on.