Free calculator widgets for your website
Put any of our 47 calculators on your own site, blog or class page. Pick one, copy the code, paste it into an HTML block. Free, no sign-up, no ads inside the widget.
Preview
How to add it
- Choose a calculator and colors above. The preview shows exactly what your visitors will see.
- Copy the code and paste it where you want the calculator, using your site builder's HTML or embed block. In WordPress that is the Custom HTML block.
- Leave Height on Fixed if your site strips scripts (many hosted blogs do). Auto-resize grows and shrinks the frame as answers change.
What's inside the widget
The same calculator and math as the full page, which is covered by automated tests against known reference values. Calculations run in your visitor's browser: nothing they type is sent to you or to us, and the widget loads no ads, cookies or trackers.
The code includes a small credit line under the widget, "by PlainCalc", linking to the full calculator with its formula and worked example. Please keep it visible; it is how other people find the tool. You may add rel="nofollow" to the link if your site's policy requires it.
Questions
Is it really free?
Yes, for personal, school, nonprofit and business sites.
Can I preset the numbers?
Yes. Open the full calculator, enter your numbers, press "Copy link to these numbers", and copy everything after the ? onto the end of the widget's src address, joined with &.
Will it slow my page down?
The widget is plain HTML with two small scripts and loads lazily, only when a visitor scrolls near it.
Something is wrong or missing.
Tell us which calculator and the numbers you entered.