Quick Calculators

Small calculations that add up to real time saved

Some math is too small to open a spreadsheet for, but easy enough to get slightly wrong doing it in your head — splitting a bill fairly, converting a recipe from metric to imperial, working out exactly how many days until a deadline, or totaling up a week's worth of hourly pay. Quick Calculators covers five of the most commonly needed everyday calculations, each computed instantly as you type.

Every calculator here runs entirely inside your browser using standard, precise math — not rounded rules of thumb. A kilogram-to-pound conversion uses the exact defined conversion factor rather than "just multiply by two," a tip calculator splits a bill down to the cent, and an age calculation accounts for leap years and varying month lengths automatically, the same way any properly written date calculation should. Nothing you type into any of these tools — a bill amount, a birth date, an hourly rate — is ever sent anywhere; the result appears the instant you finish typing, computed locally on your own device.

Because there's no server step involved, there's also no limit on how many times you can use any of these, no account needed, and no ads interrupting a calculation you need quickly. Whether you're checking a discount at checkout, converting a unit for a recipe, or double-checking a paycheck against hours actually worked, these five tools are built for the kind of quick, in-the- moment math that doesn't warrant opening anything heavier — the kind of thing you'd otherwise reach for a calculator app or a scrap of paper to figure out.

Each calculator below has its own dedicated page with more detail on how it works — click through to get started, and expect an answer the moment you finish typing, with no button to press and no page to reload.