About Life Calculator

Life Calculator publishes free calculators for the decisions of ordinary life: what a payment really costs, what a job actually pays per hour, how long a shift was, what an appliance adds to the electricity bill, whether a trip is worth driving, how fast you ran. Every tool is free, there is nothing to sign up for, and nothing you type ever leaves your browser.

We built the site because most calculators on the open web are black boxes. You enter numbers, a figure appears, and you have no way to tell whether it is right, what assumptions produced it, or what it quietly leaves out. That is not a small problem: the assumptions are usually where the whole answer lives.

#What makes these different

The formula is on the page. Every calculator writes out the equation it uses and defines every symbol. If the tool says a $380,000 house at 6.5% over 30 years costs $1,921 a month in principal and interest, the amortization formula that produced that number is directly underneath, along with a worked example you can reproduce on a pocket calculator.

We work an example by hand. Not a screenshot of the widget -- an actual step-by-step calculation with real numbers. If our arithmetic and yours disagree, one of us is wrong and you can find out which.

We never invent your rates. Electricity prices, fuel prices, mortgage rates, savings yields and inflation all change constantly and vary enormously by location. No calculator here fills one in and presents it as current. You enter the figure from your own bill or quote, and the page explains exactly where to find it. This is also why our pages do not go stale the way most calculator pages do.

We state what the model misses. Every tool ends with its limitations, written plainly: the payback calculator that ignores financing, the BMI figure that cannot see body composition, the affordability rule no lender is obliged to follow. A calculator that hides its assumptions is worse than no calculator, because it produces false confidence.

Nothing you type is transmitted. Every calculation runs in JavaScript inside your browser. There is no account, no server-side processing, no form that sends anything anywhere. You can disconnect from the network and the tools still work.

#What we do not do

We do not sell anything. No affiliate links. No memberships, no courses, no mailing list. No "get a quote" button that quietly passes what you entered to a broker, and no lead form of any other description. Running costs are met by display advertising bought through an automated exchange, which means nobody who advertises here has any say over which calculators exist or what a page concludes.

We are not licensed financial advisers, accountants, tax preparers, attorneys, engineers, physicians or dietitians, and we do not present ourselves as any of those. We build calculators and explain the mathematics behind them. Anything that hinges on the particulars of your own situation needs a qualified professional with those particulars in front of them. The disclaimer sets the boundaries of what this site is for.

#Who builds this

Calculators are specified, built, tested and documented by the Life Calculator team. You will not find a personal byline on these pages, and that is deliberate. Nothing ships until it has been through the identical sequence -- a written specification, an implementation, numerical testing against the documented formula by someone who did not write the code, and an explanation checked line by line against what the code actually does -- so responsibility for a finished tool belongs to the whole team rather than to whoever happened to type it. Our build and testing method describes that sequence in detail.

#Corrections

If a calculator returns something that looks wrong, or a formula on a page does not match the tool's behavior, we want to know immediately. Numerical errors are the most serious kind of mistake this site can make. The corrections policy explains what happens next, and the contact page is the fastest way to reach us.