Make every number make sense.

What we believe

• Clarity first. Every result says what it means in plain language, and every page shows the formula and a worked example.
• Transparent assumptions. We tell you what each calculator includes and what it leaves out.
• Private by default. Calculations run in your browser. We don't ask for your email or save what you type.
• Estimates, not advice. Our tools help you understand your numbers. For decisions about your money, health or taxes, a qualified professional can look at your full situation.

How we check our math

Each formula is written from published sources such as the IRS, the Social Security Administration and standard financial and scientific definitions. Every calculator's math is covered by automated test cases with worked answers, and figures that change each year, like tax brackets, are reviewed every January. Each page shows which year's figures it uses.

Found a mistake?

We'd like to hear about it. Contact us and we'll look into it.