Calculators & Converters

Nine calculators in one: X% of Y, X is what percent of Y, percentage change, add or subtract a percent, reverse percentage, percent difference, percentage points, ratio solver and fraction to percent, with working shown.

Calculate the tip and total, split evenly or by what each person ordered, tip on pre-tax or original price, round the total or per person, and check tipping customs in 12 countries.

Calculate sale price with stacked % and fixed coupons, tax and quantity; find the discount % or original price; value buy-one-get-one deals; and compare up to 8 deals by unit price.

Find what you need on the final exam for each letter grade, calculate weighted course grades with points or percentages, see the average needed on remaining work, and calculate term and cumulative GPA with honors/AP weighting.

A fun love calculator with four methods: name compatibility, the classic FLAMES game with steps, zodiac sign match and numerology life-path numbers. Save a share image or copy your result.

Free birth chart calculator: get your natal chart wheel with Sun, Moon and rising sign, houses, aspects and a full reading. Includes compatibility (synastry), composite, transits forecast, progressions, solar return and a Vedic kundli with dashas.

BMI calculator with WHO and Asian cut-offs, a live gauge, healthy weight range, US Navy body-fat %, waist ratios, four ideal-weight formulas, BMR and a saved progress chart.

Calculate BMR (Mifflin, Harris-Benedict, Katch-McArdle) and TDEE, set a pace in kg or lb per week, and get a macro plan with per-meal targets, water, fiber and a 26-week projection to your goal weight.

Compare heights of people, celebrities, animals and landmarks side by side to scale. Drag to reorder, add photos, shoes and builds, see exact differences, check your height percentile by country and predict a child's adult height.

Convert cm, inches, feet, meters, km and miles plus survey, nautical, typography and astronomy units. Type 5'9" or 1m 75cm, read fractions to 1/64 inch, and export conversion charts.

Convert kilograms, pounds, stone, ounces and grams plus troy ounces, carats, tola, masha, ratti, seer and maund. Includes cups-to-grams for 18 ingredients, gold karat purity and a body-weight chart.

Convert °C, °F, K, °R, Réaumur, Delisle, Newton and Rømer, switch to Δ mode for temperature differences, and calculate heat index, wind chill and dew point. Includes oven gas marks and a reference chart.

Convert square feet, meters, acres and hectares plus regional land units: marla (choose 225/250/272.25 sq ft), kanal, murabba, bigha by state, katha, guntha, cent, ropani, dunam and more. Includes an irregular plot area calculator.

Convert pixels to inches, cm, mm, points and rem at any DPI, check how large a photo will print and whether it's sharp enough, get paper sizes in pixels, and calculate screen PPI with a card-calibrated ruler.

Free PPI calculator: pixel density, dot pitch, screen size, retina distance and OS scaling from any resolution, a to-scale screen size comparison and a TV viewing distance calculator.

Calculate exact age in years, months and days with live totals, age on any past or future date, next birthday countdown, Hijri (lunar) age, 10,000-day milestones and age difference between two people.

Count calendar days, working days and each weekday between two dates with Sat-Sun, Fri-Sat or custom weekends and holidays, or add and subtract years, months, weeks, days or business days.

DST-aware time zone converter and world clock. Search 120+ cities or any IANA zone, scrub through the day, see working-hour overlap, upcoming DST changes, and send the time to Google Calendar or .ics.

Convert between Gregorian (Miladi), Persian Shamsi/Jalali, Islamic Hijri with Umm al-Qura or civil rules and moon-sighting adjustment, Julian and JDN. Dual-calendar month view, date math, differences and upcoming Ramadan, Eid and Nowruz.

Material calculator for concrete, gravel, sand, topsoil, mulch and more. Add slabs, round areas, rings, triangles and steps, include waste and compaction, and get bags, weight, truckloads, cost and site-mix cement, sand and aggregate.

List your appliances to estimate kWh and your monthly bill with flat, tiered slab or peak/off-peak tariffs, fixed charges and taxes. See cost per appliance, standby waste, CO₂, and upgrade payback.

Trip fuel cost with multiple stops, round trip, tolls, parking, passengers and fuel stops; commute cost per year; petrol vs diesel vs EV comparison; and real fuel economy from your fill-up, in MPG, km/L or L/100km.

Generate secure passwords, memorable passphrases, pronounceable passwords and PINs, or test your own password for weak patterns, real crack time and data-breach exposure. Runs in your browser.

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.