Free Calculator Widgets for Your Website
Writing about money? Add a working calculator to your article with one line of HTML. The widgets below are free for any site, load lazily from a global CDN, and contain no ads, no tracking, and no signup — just the calculator and a small attribution link.
Mortgage Payment Calculator ($)
Full monthly payment — principal and interest, property tax, insurance, and PMI when the down payment is under 20% — plus lifetime interest. Full version: upaman.com/us-mortgage-calculator
<iframe src="https://upaman.com/embed/us-mortgage" width="100%" height="560" style="border:0;max-width:520px" title="Mortgage Payment Calculator ($)" loading="lazy"></iframe>
Paycheck Calculator ($)
Take-home pay for all 50 states with 2026 federal brackets, FICA, and state income tax, shown per year, month, bi-weekly, or week. Full version: upaman.com/us-paycheck-calculator
<iframe src="https://upaman.com/embed/us-paycheck" width="100%" height="520" style="border:0;max-width:520px" title="Paycheck Calculator ($)" loading="lazy"></iframe>
401(k) Growth Calculator ($)
Projects a 401(k) to retirement age with employer match, annual raises, and compounding — separating your money, the match, and market growth. Full version: upaman.com/us-401k-calculator
<iframe src="https://upaman.com/embed/us-401k" width="100%" height="560" style="border:0;max-width:520px" title="401(k) Growth Calculator ($)" loading="lazy"></iframe>
VAT Calculator (EU/UK)
Adds or strips VAT at the standard rate for 15 European countries, showing the net, the VAT, and the gross side by side. Full version: upaman.com/eu-vat-calculator
<iframe src="https://upaman.com/embed/eu-vat" width="100%" height="460" style="border:0;max-width:520px" title="VAT Calculator (EU/UK)" loading="lazy"></iframe>
Compound Interest Calculator
Initial deposit, monthly contributions, and monthly compounding — future value, total contributed, and interest earned. Full version: upaman.com/compound-interest-calculator
<iframe src="https://upaman.com/embed/compound-interest" width="100%" height="430" style="border:0;max-width:520px" title="Compound Interest Calculator" loading="lazy"></iframe>
Hourly to Salary Calculator
Converts an hourly rate into annual, monthly, bi-weekly, and weekly pay with adjustable hours and weeks. Full version: upaman.com/hourly
<iframe src="https://upaman.com/embed/hourly-to-salary" width="100%" height="430" style="border:0;max-width:520px" title="Hourly to Salary Calculator" loading="lazy"></iframe>
SIP Calculator (₹)
Projects a monthly SIP into a corpus with invested amount and estimated gains, using the standard annuity-due formula. Full version: upaman.com/sip-calculator
<iframe src="https://upaman.com/embed/sip" width="100%" height="400" style="border:0;max-width:520px" title="SIP Calculator (₹)" loading="lazy"></iframe>
EMI Calculator (₹)
Monthly EMI, total interest, and total payable for any loan amount, rate, and tenure. Full version: upaman.com/loan-calculator
<iframe src="https://upaman.com/embed/emi" width="100%" height="430" style="border:0;max-width:520px" title="EMI Calculator (₹)" loading="lazy"></iframe>
Frequently asked questions
Are these widgets really free?
Yes — free for any website, commercial or personal, with no signup, API key, or usage limit. The only requirement is that the small "Powered by Upaman" attribution link inside the widget stays visible.
Will the widget slow my page down?
No. Each widget is a small static page served from a global CDN, contains no ads and no analytics, and the snippet uses loading="lazy" so the iframe only loads when it scrolls into view.
Can I change the size or styling?
You can set any width and height on the iframe — the widget is responsive up to 520px wide. The internal styling is fixed so the numbers always render correctly; if you need a custom-branded version, reach out via the contact page.
Do the calculators stay up to date?
Yes — the widgets are maintained alongside the full calculators on this site, so formula changes and fixes apply to your embedded copy automatically. Pure-math widgets like these have no yearly tax data to go stale.
Want a calculator that isn’t here yet as a widget — mortgage, debt payoff, income tax? Ask via the contact pageand we’ll consider it for the next batch.