Everyday & Planning tools

Solve the three everyday percent questions — X% of Y, X as a percent of Y, and percent change — side by side with live results.

Calculate BMI from metric or imperial height and weight, see the WHO category, and the healthy weight range for your height.

Turn a birth date into an exact age in years, months, and days, with totals and a next-birthday countdown.

Count the days between two dates — total, weekdays-only, and a Y/M/D breakdown — or add and subtract days from a date.

Convert between units of length, weight, temperature, area, volume, speed, time, storage, energy, and pressure with a common-values table.

Generate random numbers in any range using the browser's crypto source, with no-repeat and sort options.

Roll any combination of standard dice with modifiers, type notation like 3d6+2, and keep a roll history.

Flip up to 100 virtual coins at once with a running heads/tails tally, percentages, and streak tracking.

Convert a date and time from one time zone to many at once, with UTC offsets and day-change badges.

A timestamp-accurate online stopwatch with start, stop, lap, and reset, plus a lap table with splits and totals.

Set hours, minutes, and seconds or a quick preset; get a big countdown, a progress bar, a tab-title timer, and a beep at zero.

Estimate BMR and daily maintenance calories with the Mifflin-St Jeor equation, plus loss and gain targets.

Add courses with credits and letter grades to compute a credit-weighted GPA, with an editable 4.0 grade scale.

Track a weighted course grade from assignment scores and solve what you need on the final to hit a target.

Calculate swimming pool volume in gallons and liters for rectangular, round, and oval pools with constant or sloped depth.

Convert tank dimensions in inches or centimeters to gallons and liters, with filled weight and common tank presets.

Estimate total fabric yardage from your pattern pieces, bolt width, layout efficiency, and pattern repeat allowance.

Compute a package's dimensional weight from its size and divisor, and see whether dim or actual weight gets billed.

Work out how many boxes fit a pallet: best 90° orientation per layer, layer count, total boxes, and volume utilization.

Estimate how long a propane tank lasts for your grill, heater, or generator, and what each hour of use costs.