Put a calculator on your site

Eleven free calculators you can embed anywhere: a library resource page, a class site, a client resources page, a blog post. One line of HTML each, and nothing to sign up for.

Pick one

Investment growth calculatorA lump sum, regular contributions, or contributions that step up each year, compounded over time, with an optional inflation adjustment. Compound interest calculatorInterest on interest, at daily, monthly, quarterly or annual compounding. Mortgage calculatorMonthly payment, amount borrowed and total interest. Car loan calculatorMonthly payment and total interest on a vehicle loan. Student loan calculatorMonthly payment, payoff time, and the effect of paying extra each month. Refinance calculatorA current mortgage against a new rate and term, side by side. CAGR calculatorCompound annual growth rate between a starting and an ending value. Rule of 72 calculatorHow long money takes to double at a given rate, or the rate that doubles it in a given time, with the exact figure alongside the estimate. Inflation calculatorWhat an amount will be worth in today's money after inflation. FIRE calculatorYour FIRE number, the year you reach it as expenses rise with inflation, your savings rate and an optional Coast FIRE number. Withdrawal plannerHow long a balance lasts at monthly, quarterly or yearly withdrawals, or how much you can take out for a set number of years or indefinitely.

What they have in common

Each fills whatever width you give it, down to phone screens.
They follow your reader's light or dark mode automatically.
They do not track your visitors. No cookies and no analytics. Calculators with a chart also load Chart.js, the open-source chart library, from cdnjs, which sets no cookies.
Free on any site, including commercial ones. The credit line under each widget is optional.

Questions

Email contactus@smartfin.fyi. If you need a calculator that isn't here, say which one and why, since that genuinely shapes what gets built next.