About Free Life Tools

Free Life Tools is a small, independent site with a narrow mission: free calculators for consequential everyday decisions, each one accompanied by an honest explanation of the math it runs and the assumptions it makes.

Why the site exists

Most online calculators hand you a number with no context. That's backwards — the number is the easy part. What people actually need to know is whether the assumptions fit their situation: whether the payback period in a solar quote assumed realistic electricity inflation, whether a "you can afford this house" figure came from a lender's ceiling or a sane budget, whether a calorie target was built on maintenance calories or a number that describes a coma patient. Every tool on this site states its formula, walks through a worked example with real numbers, and — where the honest answer is "this calculator can't tell you that" — says so directly.

Where the formulas come from

Nothing here is invented. The financial tools use the standard amortization and compound-interest mathematics that lenders and banks themselves use, plus widely documented frameworks like the 28/36 affordability rule and the 50/30/20 budget split (whose origins and limits we write about honestly). The health tools use published, validated equations — the TDEE calculator runs Mifflin-St Jeor, the equation with the strongest validation record, and the BMI page spends as many words on the measure's documented failure modes as on the measure itself. Each calculator page names its method so you can verify it independently.

How the site is funded

Advertising. The calculators are free, require no account, and collect no personal information — every calculation runs in your browser and is never transmitted or stored. Ads keep it that way. We don't accept payment from lenders, solar installers, or anyone else to influence what the tools say; no affiliate commissions shape the recommendations, and several pages actively warn readers about the sales tactics of industries that would presumably prefer we didn't.

What this site is not

Not financial advice, not medical advice, and not a substitute for professionals who can see your whole situation. Calculators are excellent at arithmetic and blind to context. Where a decision is big enough that context dominates — refinancing, buying a home, aggressive dieting — the pages here say so and point toward the right kind of professional.

Corrections

If you find an error — in a formula, a worked example, or a claim in an article — please tell us. Corrections are made promptly and without ego. A calculator site that gets math wrong should hear about it loudly.