Calculators
Quick, accurate calculators for everyday numbers.
- Absolute Value CalculatorInstantly find |x| โ the absolute value of any number, free.
- Age CalculatorYour exact age in years, months, and days โ updated live
- Angle ConverterConvert degrees, radians, gradians, turns, arcmin & arcsec
- Annulus Area CalculatorInstantly find the area of a ring (annulus) with ฯ(Rยฒ โ rยฒ).
- Area ConverterConvert square meters, feet, acres & hectares instantly
- Average CalculatorMean, median, mode & more from any list of numbers, instantly
- Baby Eye Color CalculatorPredict your baby's eye color odds from both parents' eyes
- Online CalculatorDo quick everyday math in your browser โ free, private, no signup.
- Bra Size CalculatorGet your US, UK & EU bra size from two measurements.
- Brinell Hardness CalculatorBrinell hardness number (BHN/HBW) from load, ball & indent
- Business Days CalculatorCount business days between two dates, skipping weekends
- Cat Age CalculatorConvert your cat's age to human years the vet-approved way
- Chinese Gender PredictorSee a fun boy-or-girl guess from the Chinese gender chart
- Circle Area CalculatorFind a circle's area from its radius or diameter โ A = ฯrยฒ.
- Circumference CalculatorFind a circle's circumference from its radius or diameter
- Clothing Size ConverterConvert women's & men's sizes across US, UK and EU charts
- Cone Surface Area CalculatorTotal and lateral surface area of a cone from radius and height
- Cone Volume CalculatorInstantly find the volume of a cone with V = (1/3)ฯrยฒh.
- Cube Root CalculatorFind the cube root (โx) of any number, including negatives
- Cube Volume CalculatorFind the volume of a cube from its side length using V = sยณ.
- Curtain Fabric CalculatorWork out fabric widths and total length for your curtains.
- Cylinder Surface Area CalculatorInstantly get a cylinder's total, lateral, and base area
- Cylinder Volume CalculatorGet the volume of a cylinder from radius and height instantly
- Data Storage ConverterConvert bytes, KB, MB, GB, TB, PB โ binary or decimal
- Date Add Subtract CalculatorAdd or subtract days, weeks, months, or years from any date.
- Date Difference CalculatorCount days, weeks, and months between any two dates.
- Date Format ConverterConvert a date into ISO, US, EU, long, and word formats.
- Day of the Week CalculatorFind what day of the week any past or future date falls on.
- Day of Year CalculatorSee what day number of the year any date is, plus ISO week.
- Density ConverterConvert g/cm3, kg/m3, lb/ft3 and more density units
- Dog Age CalculatorConvert your dog's age to human years by breed size.
- Ellipse Area CalculatorEllipse area from its two semi-axes โ A = ฯยทaยทb.
- Energy ConverterConvert joules, calories, kcal, kWh, BTU, eV and more
- EV Charging Cost CalculatorEstimate what it costs to charge your EV, losses included.
- Exponent CalculatorRaise any base to any power instantly, with the steps
- Flooring CalculatorWork out how much flooring and how many boxes to buy.
- Force ConverterConvert newtons, kN, kgf, lbf, dyne, poundal and kip
- Fraction CalculatorAdd, subtract, multiply or divide fractions instantly
- Frequency ConverterConvert Hz, kHz, MHz, GHz, THz, rpm, rad/s and BPM
- Gas Mileage CalculatorGet your MPG and L/100km from distance and fuel used.
- GCF CalculatorFind the GCF/GCD and LCM of any integers, with steps
- GPA CalculatorWeighted GPA from your letter grades and credit hours.
- GPS Coordinates ConverterConvert coordinates between decimal degrees and DMS.
- Grade CalculatorTurn your scores and weights into a grade and letter.
- Hardness Conversion CalculatorConvert HRC, HRB, Vickers and Brinell steel hardness.
- Hemisphere CalculatorGet hemisphere volume and surface areas from the radius
- Hexagon Area CalculatorRegular hexagon area from its side โ A = (3โ3/2)ยทsยฒ.
- Ideal Weight CalculatorIdeal body weight by height and sex, four proven formulas.
- LCM CalculatorFind the LCM of any integers, with steps and the GCF
- Leap Year CalculatorInstantly check whether any year is a leap year.
- Length ConverterConvert cm, mm, m, km, inches, feet, yards & miles
- Logarithm CalculatorCompute a log in any base, plus ln, log10 and log2
- Love CalculatorGet a fun love score from two names in seconds.
- Metal Weight CalculatorWeigh metal bar, pipe, tube, sheet & hex from size
- Military Time ConverterConvert 12-hour AM/PM to and from 24-hour military time.
- Number Base ConverterConvert integers between binary, octal, decimal & hex
- Pace CalculatorGet your running pace in min/km and min/mile fast.
- Paint CalculatorWork out how much paint you need for your walls.
- Paper Enlargement Percentage CalculatorCopier scaling % between A4, A3, Letter & more
- Paper Weight ConverterConvert paper GSM to lb basis weight, by paper type
- Parallelogram Area CalculatorArea of a parallelogram โ A = bยทh or aยทbยทsin(ฮธ).
- Percentage CalculatorFind X% of a number, a percent of a total, or % change
- Interactive Periodic TableExplore all 118 elements โ data, colors, and instant search
- Pi DigitsShow the first N digits of pi, up to 10,000 decimals
- Power ConverterConvert watts, kW, MW, hp, BTU/h, ftยทlbf/s and more
- PPI CalculatorCalculate your screen's pixel density (PPI) in seconds
- Pressure ConverterConvert pressure between Pa, kPa, bar, psi, atm & mmHg
- Prime Factorization CalculatorFactor any integer into primes with an instant factor tree
- Prime Number GeneratorGenerate prime numbers up to N or the first N primes
- Pixels to CM ConverterConvert pixels to cm, inches and mm at any DPI value
- Pythagorean Theorem CalculatorUse aยฒ+bยฒ=cยฒ to find a right triangle's hypotenuse or leg
- Ratio CalculatorSimplify any ratio and solve proportions a : b = c : x
- Rectangle Area CalculatorGet the area, perimeter and diagonal of any rectangle instantly
- Rectangular Prism Volume CalculatorGet rectangular prism volume, surface area & diagonal
- Retirement Date CalculatorRetirement date and countdown from your birth date and age
- Scientific CalculatorA full scientific calculator that evaluates trig, logs, powers, roots and factorials right in your browser โ no sign-up, no server round-trip.
- BMI CalculatorGet your BMI and WHO weight category instantly in metric or imperial units.
- Calorie CalculatorEstimate how many calories you need per day to lose, maintain, or gain weight โ Mifflin-St Jeor TDEE, computed instantly in your browser with nothing uploaded.
- BMR CalculatorSee your resting calorie burn from two trusted equations, side by side.
- Pregnancy Due Date CalculatorEstimate your baby's due date and current gestational age from your last period
- BAC CalculatorEstimate your Blood Alcohol Content with the Widmark formula from drinks, weight, sex, and time.
- Body Fat CalculatorEstimate your body-fat percentage from tape-measure numbers in seconds โ no calipers, scales, or gym visit needed.
- Ovulation CalculatorEstimate your ovulation day and fertile window from your last period and cycle length.
- Macro CalculatorSplit any daily calorie target into carb, protein, and fat grams using the Atwater 4/4/9 kcal/g factors.
- Target Heart Rate CalculatorFind your ideal training heart-rate zone with the Karvonen formula.
- Time Zone ConverterConvert any date and time between world time zones, fully DST-aware.
- Time Duration CalculatorFind the exact time between two dates and times, with a clear breakdown and precise totals.
- Ring Size ChartMatch your ring size across US, UK, EU and Japan systems in one click.
- Bra Size ConverterConvert a bra size across US, UK, EU, FR and AU/NZ in one click.
- Timesheet CalculatorAdd up a week of clock-in and clock-out times, breaks, and pay in seconds.
- Roman Numeral ConverterConvert numbers to Roman numerals and back instantly, with strict validation that rejects malformed forms.
- Time ConverterInstantly convert any time value across ten units โ from nanoseconds to years โ in your browser.
- Cooking Measurement ConverterConvert cooking measurements between cups, tablespoons, ounces, grams, ยฐF, ยฐC and gas mark โ instantly, all in your browser.
- Rounding CalculatorRound exact decimal text with five clearly defined modes, without binary floating-point surprises.
- Wallpaper CalculatorEstimate wallpaper by full drops and whole rolls while accounting for wall corners, trim, and vertical pattern repeat.
About these tools
Every tool in calculators runs locally in your browser: files are processed on your device and never uploaded to a server. That makes them fast, private and safe to use with sensitive documents, at work or at home.