Percentage
What is x percent of y, what percent is a of b, and the percentage change from A to B.
Open a calculatorBrowse by group
Everyday numbers
Units, school math and physics, dates, fuel and a breathalyzer sketch.
Percent change
How much a figure moved, as a percent of the starting value.
Open a calculatorTrigonometry
Sine, cosine and tangent of an angle in degrees, plus the radian.
Open a calculatorPythagoras
Fill two sides of a right triangle; the third and the area come out.
Open a calculatorQuadratic
Real roots of a quadratic, or a linear fallback if a is zero.
Open a calculatorLogarithm
log_base(x), plus the natural log and the common log.
Open a calculatorCombinatorics
Factorial, permutations and combinations for whole n and r.
Open a calculatorGCD and LCM
Greatest common divisor and least common multiple of two integers.
Open a calculatorCircle
Diameter, circumference and area from a radius.
Open a calculatorTriangle area
Area of any triangle from three sides, if they close.
Open a calculatorOhm’s law
Leave one of voltage, current or resistance empty; power comes with it.
Open a calculatorNewton’s second law
Leave one of force, mass or acceleration empty.
Open a calculatorKinetic and potential
Translational kinetic energy and gravitational potential energy.
Open a calculatorFree fall
From rest: fill time or distance, leave the other empty.
Open a calculatorIdeal gas
Leave one of P, V, n or T empty. P in kPa, V in litres.
Open a calculatorWave speed
Leave one of speed, frequency or wavelength empty.
Open a calculatorDensity
Leave one of mass, volume or density empty.
Open a calculatorSnell’s law
The second angle from two indices and an incidence angle.
Open a calculatorThin lens
Leave one of focal length, object distance or image distance empty.
Open a calculatorUnit converter
Weight, length, distance and temperature. Common units, no lookup table.
Open a calculatorCurrency
Euro, zloty, dollar and the other ECB currencies. The reference rate from the last TARGET business day.
Open a calculatorAge
Exact age today from a date of birth.
Open a calculatorDates
Days, weeks and weekdays between two dates, or a date plus a number of days.
Open a calculatorHours
Hours between two clock times, minus a break. Also add minutes to a start time.
Open a calculatorPolish workdays
Count working days between two dates, skipping weekends and Polish public holidays, or add working days to a date.
Open a calculatorTrip fuel
Litres and cost for a trip from distance, consumption and price.
Open a calculatorCommute cost
A month of two-way driving from litres and parking, set against a season ticket.
Open a calculatorCar running cost
Yearly and monthly cost of keeping a car, including straight-line depreciation.
Open a calculatorCar lease payment
A monthly lease from price, down payment, residual value and APR.
Open a calculatorBreathalyzer
A drink diary with clock times. Estimated ‰ at the hour you choose. A model, not a device.
Open a calculatorAlcohol units
Grams of ethanol, 10 g drinks and UK units from volume and ABV.
Open a calculatorTime on the road
Hours and minutes for a distance at a constant speed.
Open a calculatorMonthly fuel
Litres and the bill for a month of kilometres.
Open a calculatorRecipe scale
Scale one amount from the servings the recipe was written for.
Open a calculatorUnit price
Which pack is cheaper per unit, and by what percent.
Open a calculatorPaint needed
Litres from wall area, coats and the tin’s m² per litre.
Open a calculatorFlooring
How many packs of floor from room area, waste and the box coverage.
Open a calculatorDew point
The Magnus dew point from indoor or outdoor air temperature and relative humidity.
Open a calculatorWind chill
How cold it feels from air temperature and wind speed.
Open a calculatorWallpaper
How many rolls from wall perimeter, height, roll size and waste.
Open a calculatorConcrete slab
Cubic metres for a rectangular slab, with a waste percent.
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