Calculators tools

Find the date a number of days, weeks or months before or after another date.

Calculate exact age in years, months and days, plus total days and the next birthday.

Calculate area, perimeter and volume for circles, rectangles, triangles and common solids.

Scale width and height while keeping the aspect ratio, and identify the ratio itself.

Find the mean, median, mode, range and standard deviation of a list of numbers.

Estimate how long a battery will last from its capacity and the current a device draws.

Work out the document size with bleed, the safe area inside the trim, and the finished size after cutting.

Calculate body mass index from height and weight, in metric or imperial units.

Estimate resting metabolic rate and daily calorie needs from height, weight, age and activity.

Decode the three-digit code on a ceramic capacitor into picofarads, nanofarads and microfarads.

Work out a monthly car payment from price, deposit, trade-in, tax, fees and APR, with the total interest shown.

Project savings or investment growth with compounding and optional monthly contributions.

Work out the concrete volume for a slab, footing or column, in cubic metres and yards.

Count the days, weeks and months between two dates, with and without weekends.

Project an asset's value year by year using straight-line or declining balance depreciation.

Work out a sale price from a discount percentage, and how much is saved.

Find the great-circle distance and bearing between two sets of coordinates.

Work out what an appliance costs to run, per day, month and year, from its wattage.

Work out what charging an electric car costs, per charge and per mile or kilometre.

Estimate an electric car's real range from battery size, efficiency, temperature and the charge you keep in reserve.

Raise numbers to a power, take any root, and calculate logarithms.

Work out force from mass and acceleration, or weight from mass under gravity, in newtons and pounds-force.

Add, subtract, multiply or divide two fractions and simplify the result.

Estimate the fuel cost of a journey from distance, economy and fuel price.

Find the greatest common divisor and lowest common multiple of several numbers.

Divide a length by the golden ratio, or extend it, with a sequence of proportional steps.

Work out gravel, mulch, sand or topsoil needed by volume and weight, with bag counts.

Work out training heart rate zones from age and resting heart rate.

Compare healthy weight ranges for your height across several established formulas.

See what an amount is worth after inflation over a number of years.

Work out bread ingredient weights from baker's percentages, including hydration, salt, yeast and starter.

Estimate jet lag recovery from the time zones crossed and direction, with a pre-adjustment schedule.

Work out how many packs of laminate or vinyl flooring a room needs, with a cutting allowance.

Work out the series resistor an LED needs, with the nearest standard value and its power rating.

Find a line height and column width for a font size, from the number of characters per line.

Calculate the monthly repayment, total interest and total cost of a loan from amount, rate and term.

Calculate board feet and cost for timber, or the number of studs a wall needs at a given spacing.

Split a daily calorie target into protein, carbohydrate and fat, by ratio or by body weight.

Monthly mortgage payment including tax and insurance, with total interest over the term.

Solve for voltage, current, resistance or power from any two known values.

Convert an oven temperature between Celsius, Fahrenheit, gas mark and fan-assisted settings.

Calculate overtime pay at time-and-a-half or any multiplier, with total weekly pay.

Estimate how much paint a room needs, allowing for coats, doors and windows.

Convert any standard paper size between millimetres, inches, points and pixels at a chosen resolution.

Work out a percentage of a number, what percentage one number is of another, and percentage change.

Work out pressure from a force and a contact area, in pascals, bar, psi and atmospheres.

Check whether a number is prime and break it into its prime factors.

Work out the printable area and content width left on a page after margins and binding gutter.

Work out how large an image can be printed at a given resolution, in inches, centimetres and standard photo sizes.

Combine two event probabilities, and find the chance of at least one occurrence over repeated trials.

Solve ax² + bx + c = 0, with the discriminant and vertex shown.

Simplify a ratio, scale it up, or solve for a missing value.

Work out how much food to cook for a number of people, by course and appetite.

Scale a recipe up or down by servings, rewriting every quantity as a fraction a kitchen can measure.

Read a resistor's value from its colour bands, with tolerance and the range it may fall in.

Find the pixel dimensions and megapixels needed to print at a given size and resolution.

Project a retirement pot from monthly contributions, and what it might pay out.

Work out roof area from the footprint and pitch, in squares and bundles, with a waste allowance.

Calculate a room's floor area, wall area and volume in metric and imperial units.

Convert between spindle RPM, cutting speed, surface speed and pulley ratios.

Work out pace, finish time or distance for a run, with splits for common races.

Add tax to a net price or strip it out of a gross price at any rate.

Evaluate expressions with brackets, powers, roots, logs, trigonometry and factorials, in degrees or radians.

Work out simple interest and the final balance from principal, rate and time.

Solve for speed, distance or time, with pace per kilometre and per mile alongside.

Work out stair rise, going and total run, and check them against building regulations.

Work out how many tiles a floor or wall needs, including a wastage allowance.

Work out a tip and split the bill between any number of people.

Compare two tire sizes for diameter, sidewall, circumference and the speedometer error the change causes.

Work out torque from a force, a lever length and the angle it is applied at, in N·m and lb·ft.

Add up a trip's cost from flights, accommodation and daily spending, with a contingency and a per-day figure.

Work out nights, days and the annual leave a trip actually costs, from departure and return dates.

Build a modular type scale from a base size and ratio, in pixels and rem, with line heights.

Compare products by price per unit to find which is genuinely cheaper.

Work out variance, standard deviation, quartiles and outliers from a list of numbers.

Calculate the output voltage of a two-resistor divider, with current draw and loading advice.

Count working days between dates, or find the date a number of working days away.