Calculators & Converters

Calculate percentages five ways: what X% of Y is, what percent one number is of another, percentage change, add/subtract a percent, and multi-part ratio splits, with formulas shown, free, in your browser.

Free tip calculator. Work out the tip and total for a bill, split it between any number of people, with quick tip presets and a round-up option. Instant, no signup.

Free discount calculator. Enter a price and discount to see the final sale price and savings, with optional stacked coupon and sales tax. Instant, no signup.

Find exactly what score you need on your final to hit your target grade, or add up weighted categories to see your current grade and letter, free, instant, and private.

Free love calculator. Enter two names for a fun compatibility percentage, FLAMES result, sub-score bars, and optional zodiac star-sign compatibility, just for fun, runs instantly in your browser.

Calculate your Body Mass Index (BMI) in metric or imperial units with a live category gauge, healthy weight range, weight-to-goal, ideal-weight formulas, BMR, and waist-to-height risk, free.

Calculate your TDEE, maintenance calories, and daily macros for weight loss, muscle gain, or maintenance. Uses Mifflin-St Jeor (or Katch-McArdle with body fat), projects weekly weight change, and sets a water target, free, private, local-only.

Convert length units between centimeters, inches, feet, meters, kilometers, miles, yards, nautical miles, and more, every unit shown at once. Free, instant, high-precision.

Convert between kilograms, pounds, ounces, grams, stones, tonnes, and US tons, every unit shown at once. Free, instant weight & mass converter for cooking, fitness, shipping, and science.

Convert temperatures between Celsius, Fahrenheit, Kelvin, and Rankine instantly, all scales shown at once. Free online temperature converter for cooking, science, and weather.

Convert between area units, square feet, square meters, square yards, acres, hectares, and South Asian land units like Marla and Kanal, with every unit shown at once. Free, instant.

Convert pixels to inches, cm, mm, points, picas, and rem based on your DPI/PPI and root font size, every unit shown at once. Essential for print sizing, web design, and CSS typography.

Calculate your exact age in years, months, and days, plus totals in weeks, days, hours, minutes, and live seconds. See the weekday you were born, your zodiac signs, and a countdown to your next birthday.

Free days between dates calculator. Find the exact days, weeks, months, years and business days between two dates, with an option to include the end date.

Convert a chosen time across many cities at once with UTC offsets, day/night, and a meeting-overlap planner, or run it live. Daylight saving is handled automatically. Free, real-time.

Free advanced date converter. Convert instantly between Shamsi (Persian), Islamic (Hijri), Gregorian (Miladi), Julian Day Number and the Julian calendar, with date math, day difference, leap-year flags and copy-to-clipboard. Private, no signup.

Calculate how much concrete, gravel, mulch, topsoil, or sand you need for rectangular or circular areas, with volume, weight, bags, waste allowance, and total cost. Free and local.

Calculate how much any appliance costs to run, per day, month, and year. Enter the wattage, hours of use, and your electricity rate to see the true cost. Free and private.

Estimate the fuel cost of any trip. Enter the distance, your vehicle's fuel economy, and fuel price to see total cost, split it between passengers and add a return leg. Free and local.

Generate strong, secure passwords, memorable passphrases, and PINs, then check password strength. Shows true entropy in bits and estimated crack time, free, local only, nothing stored.

Roll 1-12 dice (d4-d100, custom sides) with D&D notation, advantage, and exploding dice. Flip up to 100 coins at once, instant, fair, private, no download.