Fast, accurate, no-nonsense calculators that run entirely in your browser — nothing to install, nothing sent to a server.
Find the right tool faster, organized into four simple groups.
Short, plain-English explainers with worked examples and charts, so you know what a result means before you act on it.
Mortgages and home buying
The formula behind your monthly payment, and where each dollar goes.
Saving and investing
Why time matters more than almost anything else when you save.
Retirement
The 4% rule and the 25 times shortcut, and what they assume.
Health and fitness
Estimate BMR and daily calories, step by step.
About CalcBundle
CalcBundle is a free collection of 214 calculators for money, health, math and everyday questions. Everything runs in your browser, so the numbers you type stay on your device, and there is nothing to install or sign up for.
We build each calculator from its published formula and check it against well-known calculators and official sources, and we note where a result is an estimate. Our guides explain the maths and assumptions behind the most-used tools.