Embed Free Calculators on Your Website
You can add any calculator below to your own website, blog or course page for free. Paste two lines of HTML where you want the calculator to appear. It loads inside a frame, resizes itself to fit, and works on phones. Every embed carries a small “Powered by Momentix” link back to the full calculator, which is the only condition of use.
How to add a calculator
- Copy the code for the calculator you want from the list below.
- Paste it into the HTML of your page, where the calculator should appear.
- Save and reload the page. The calculator appears and sizes itself.
Visitors’ numbers are calculated in their own browser and are not sent to your site or ours. The embed does not set cookies or load advertising.
Available calculators
Age Calculator
Exact age in years, months and days on a chosen date, with total days lived and the next birthday.
<div data-momentix-calculator="age-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Date Difference Calculator
Days, weeks, months and years between two dates.
<div data-momentix-calculator="date-difference-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Business Days Calculator
Count business days between two dates, or add business days to a start date (Monday-to-Friday week, no holidays).
<div data-momentix-calculator="business-days-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Loan Repayment Calculator
Monthly payment and total interest on a fixed-rate loan, with the effect of extra monthly payments or a lump sum.
<div data-momentix-calculator="loan-repayment-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Compound Interest Calculator
Future value of savings with monthly deposits and compound interest.
<div data-momentix-calculator="compound-interest-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>VAT Calculator
Add VAT to a net price or remove VAT from a gross price.
<div data-momentix-calculator="vat-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>UK Take-Home Pay Calculator
UK take-home pay after income tax, National Insurance, pension and student loan (England, Wales and Northern Ireland rates for the tax year shown by the page).
<div data-momentix-calculator="uk-take-home-pay-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Mortgage Calculator
Monthly repayment, total interest and loan-to-value for a repayment mortgage.
<div data-momentix-calculator="mortgage-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Hourly to Salary Calculator
Convert an hourly rate to a salary, or a salary to an hourly rate.
<div data-momentix-calculator="hourly-to-salary-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Percentage Change Calculator
Percentage increase or decrease from an old value to a new value.
<div data-momentix-calculator="percentage-change-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Tip and Bill Split Calculator
Tip, total and each person's share of a bill.
<div data-momentix-calculator="tip-and-bill-split-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>BMI Calculator
Adult body mass index from metric height and weight, with the healthy weight range.
<div data-momentix-calculator="bmi-calculator"></div>
<script async src="https://www.momentix.online/embed.js"></script>Prefer data instead of a frame?
The same formulas are available as a read-only JSON API with no key. See the OpenAPI description or the endpoint list. You can also link visitors to a pre-filled calculator, for example https://www.momentix.online/loan-repayment-calculator?amount=10000&rate=7&term=5.