167 free calculators

Convert Miles to Kilometres instantly.

Convert Kilometres to Miles instantly.

Convert Metres to Feet instantly.

Convert Feet to Metres instantly.

Convert Inches to Centimetres instantly.

Convert Centimetres to Inches instantly.

Convert Yards to Metres instantly.

Convert Metres to Yards instantly.

Convert Nautical miles to Kilometres instantly.

Convert Millimetres to Inches instantly.

Convert Kilograms to Pounds instantly.

Convert Pounds to Kilograms instantly.

Convert Stone to Kilograms instantly.

Convert Kilograms to Stone instantly.

Convert Ounces to Grams instantly.

Convert Grams to Ounces instantly.

Convert Tonnes to Kilograms instantly.

Convert Carats to Grams instantly.

Convert Square feet to Square metres instantly.

Convert Square metres to Square feet instantly.

Convert Acres to Hectares instantly.

Convert Hectares to Acres instantly.

Convert Square miles to Square kilometres instantly.

Convert Square yards to Square metres instantly.

Convert Litres to UK gallons instantly.

Convert UK gallons to Litres instantly.

Convert Millilitres to UK fluid ounces instantly.

Convert UK fluid ounces to Millilitres instantly.

Convert UK cups to Millilitres instantly.

Convert UK pints to Litres instantly.

Convert Cubic feet to Cubic metres instantly.

Convert Cubic metres to Cubic feet instantly.

Convert Miles per hour to Kilometres per hour instantly.

Convert Kilometres per hour to Miles per hour instantly.

Convert Metres per second to Miles per hour instantly.

Convert Knots to Miles per hour instantly.

Convert Megabytes to Gigabytes instantly.

Convert Gigabytes to Megabytes instantly.

Convert Megabits per second to Megabytes per second instantly.

Convert Bytes to Kilobytes instantly.

Convert Kilojoules to Kilocalories instantly.

Convert Kilocalories to Kilojoules instantly.

Convert PSI to Bar instantly.

Convert Bar to PSI instantly.

Convert Horsepower to Kilowatts instantly.

Calculate a tip, total bill and equal cost per person.

Estimate car finance payments after a deposit, part exchange and fees.

Calculate a weighted grade point average from course grades and credits.

Turn marks into a percentage and calculate the score needed on a remaining assessment.

Find the mean, total, smallest and largest of up to six numbers.

Estimate basal metabolic rate and daily calorie needs from body measurements and activity.

Estimate body fat percentage with the circumference-based US Navy method.

Split a daily calorie target into protein, carbohydrate and fat grams.

Estimate a due date from the first day of the last menstrual period and cycle length.

Calculate elapsed time between two clock times, including overnight periods.

Estimate residential Stamp Duty Land Tax using rates applying from 1 April 2025.

Estimate asphalt volume, weight and material cost for a rectangular area.

Estimate flooring area, packs and cost including a waste allowance.

Convert Celsius temperatures to Fahrenheit.

Convert Fahrenheit temperatures to Celsius.

Convert Celsius temperatures to Kelvin.

Find a percentage of any number.

Calculate what percentage one value is of another.

Increase a number by a chosen percentage.

Decrease a number by a chosen percentage.

Measure the percentage change between an old and new value.

Work backwards from a percentage-adjusted amount to the original value.

Calculate a weighted average from three values and weights.

Reduce a two-number ratio to its simplest whole-number form.

Solve a/b = c/x for the missing value x.

Convert a fraction into a percentage.

Convert a decimal to a simplified fraction.

Split a bill and optional tip between people.

Calculate a circle's area and circumference from its radius.

Calculate rectangle area and perimeter.

Calculate triangle area from base and height.

Find the hypotenuse of a right-angled triangle.

Calculate trapezoid area from parallel sides and height.

Calculate sphere volume and surface area.

Calculate cylinder volume and total surface area.

Calculate the volume of a cone.

Calculate cube volume and surface area.

Calculate a rectangular prism's volume and surface area.

Solve ax² + bx + c = 0.

Find the slope between two coordinate points.

Calculate straight-line distance between two coordinate points.

Estimate monthly loan repayments and total interest.

Calculate investment growth with compound interest.

Calculate simple interest over time.

Estimate the monthly saving needed to reach a target.

Project an investment with regular monthly contributions.

Calculate return on investment.

Calculate gross profit and gross margin.

Calculate selling price and profit from cost and markup.

Estimate how many units are needed to cover fixed costs.

Calculate a discounted price and saving.

Add a configurable sales tax to a price.

Calculate commission and total earnings.

Convert an hourly wage to weekly, monthly and annual pay.

Convert an annual salary to an equivalent hourly rate.

Calculate standard and overtime earnings.

Estimate how inflation reduces future purchasing power.

Calculate today's value of a future sum.

Calculate the future value of a current sum.

Calculate compound annual growth rate.

Estimate how long an investment takes to repay its cost.

Measure how often average inventory is sold.

Calculate the average production cost per unit.

Calculate profit and profit margin.

Calculate revenue growth between two periods.

Calculate a property's price per square foot.

Estimate body mass index from kilograms and centimetres.

Estimate body mass index from pounds and inches.

Estimate basal metabolic rate using the Mifflin-St Jeor equation.

Estimate daily calories from BMR and activity level.

Estimate a simple daily water target based on body weight.

Calculate pace from distance and finishing time.

Calculate average cycling speed.

Estimate calories burned while walking using a MET value.

Estimate body surface area using the Mosteller formula.

Estimate the weight range corresponding to BMI 18.5–24.9.

Calculate waist circumference as a proportion of height.

Estimate a daily protein range from body weight.

Estimate journey fuel use and cost.

Convert UK miles per gallon to litres per 100 kilometres.

Convert litres per 100 kilometres to UK MPG.

Estimate travel time from distance and average speed.

Estimate paint litres from wall area, coats and coverage.

Estimate tile quantity including wastage.

Estimate wallpaper rolls from wall and roll dimensions.

Calculate concrete volume for a rectangular slab.

Estimate electricity cost from energy use and unit price.

Estimate an appliance's electricity cost.

Calculate age from a date of birth and comparison date.

Count calendar days and weeks between two dates.

Calculate overnight sleep duration.

Scale an ingredient quantity for a different number of servings.

Work out how many pizzas to order for a hungry group.

Count the days and weeks until a birthday or celebration.

Convert a dog's age into a simple human-age comparison.

Convert a cat's age into a simple human-age comparison.

See what a regular coffee habit costs over a year.

Estimate the savings from swapping some takeaways for home cooking.

Calculate how long a series marathon will take.

Estimate when you could finish a book at your usual pace.

Estimate how many songs a journey playlist needs.

Estimate drinks and packs for a party.

Turn daily recreational screen time into an annual total.

Calculate the chance of winning a simple equal-chance draw.

Estimate how regular overpayments could shorten a repayment mortgage and reduce interest.

Compare how annual fees could affect a long-term investment projection.

Project a pension pot and a simple annual withdrawal estimate.

Compare gross and net rental yield after common annual property costs.

Estimate monthly rental cash flow after mortgage and property costs.

Compare monthly debt commitments with gross monthly income.

Build a target from essential monthly costs and estimate how long saving could take.

Combine renovation work, professional costs and contingency into one budget.

Set a unit selling price that covers variable costs, overhead and a target profit.

Estimate a car's future value using a first-year and later annual depreciation rate.

Estimate simple payback from installation cost, annual generation and electricity value.

Add regular subscriptions and see their annual and five-year cost.

Use a clean, full-size calculator for everyday arithmetic, percentages and brackets.

Convert between global currencies using cached live rates or your own manual exchange rate.

Estimate UK Income Tax, National Insurance and take-home pay with a clear breakdown.

Calculate monthly mortgage repayments, total interest and a detailed payment breakdown.

Add or remove UK VAT and see the net, VAT and gross amounts instantly.

Estimate Spanish mortgage repayments, deposits and borrowing costs for UK buyers.