Convert any unit, instantly
Free unit converters and calculators with exact factors, worked examples and charts. Search for a unit below, or jump to a popular conversion or calculator.
Popular Conversions
- Centimeters to Inches
- Inches to Centimeters
- Feet to Meters
- Meters to Feet
- Kilometers to Miles
- Miles to Kilometers
- Centimeters to Feet
- Millimeters to Inches
- Kilograms to Pounds
- Pounds to Kilograms
- Stone to Kilograms
- Kilograms to Stone
- Grams to Ounces
- Ounces to Grams
- Degrees Celsius to Degrees Fahrenheit
- Degrees Fahrenheit to Degrees Celsius
- Liters to US Gallons
- US Gallons to Liters
- Milliliters to US Cups
- Milliliters to US Fluid Ounces
- Square Feet to Square Meters
- Square Meters to Square Feet
- Acres to Hectares
- Hectares to Acres
- Kilometers per Hour to Miles per Hour
- Miles per Hour to Kilometers per Hour
- US Dollars to Euros
- Euros to US Dollars
- US Dollars to British Pounds
- British Pounds to Pakistani Rupees
- Bars to Pounds per Square Inch
- Pounds per Square Inch to Bars
- Horsepower to Kilowatts
- Kilowatts to Horsepower
- Gigabytes to Megabytes
- Terabytes to Gigabytes
All Converters
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Currency
Live currency converter — US Dollar, Euro, British Pound, Pakistani Rupee, and more, from daily exchange rates.
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Length
Length converter for metric and imperial distances — millimeters up to miles.
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Weight and Mass
Mass and weight converter — milligrams up to metric tons, plus pounds, ounces, and stone.
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Temperature
Convert Celsius, Fahrenheit, and Kelvin — including the classic weather-forecast conversion.
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Volume
Volume converter for cooking and liquid measurements — milliliters up to gallons.
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Area
Area converter for land, floor space, and real estate — square feet up to acres and hectares.
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Speed
Speed converter for driving, weather, and aviation — mph, km/h, and knots.
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Time
Time converter — milliseconds up to years.
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Pressure
Pressure converter for weather, tires, and engineering — psi, bar, and atmospheres.
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Angle
Angle converter for geometry and trigonometry — degrees, radians, and gradians.
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Power
Power converter for engines and electronics — watts, kilowatts, and horsepower.
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Data Storage
Digital storage converter for files and drives — bits up to terabytes.
Popular calculators
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Mortgage Calculator
Monthly payment, total interest and a yearly schedule. US, UK and Canadian compounding.
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Loan Calculator
Payments for personal, car and student loans, with total cost and payoff schedule.
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Compound Interest Calculator
Savings growth with monthly deposits and any compounding frequency.
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Percentage Calculator
Percent of a number, percentage change, and increase or decrease by a percent.
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VAT Calculator
Add or remove VAT for the UK, Netherlands (BTW), Germany, France and Belgium.
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GST/HST Calculator (Canada)
GST, HST, PST and QST for every Canadian province and territory.
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Sales Tax Calculator (US)
Add or remove US state and local sales tax from any price.
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Tip Calculator
Tip amount, total and an even split between any number of people.
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Discount Calculator
Sale price after one or two discounts, with optional sales tax.
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Height Converter (cm to feet and inches)
Convert height between centimeters and feet and inches, with a height chart.
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Date Calculator
Days between two dates, business days, and adding or subtracting days.
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BMI Calculator
Body mass index for adults in kg/cm, lb/ft or stone, with waist-to-height ratio.
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Calorie Calculator
Daily calories to maintain, lose or gain weight (TDEE, Mifflin-St Jeor).
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BMR Calculator
Basal metabolic rate by Mifflin-St Jeor, Harris-Benedict and Katch-McArdle.
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Body Fat Calculator
Body fat percentage with the US Navy tape-measure method.
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Ideal Weight Calculator
Healthy weight range for your height, plus Devine, Robinson, Miller and Hamwi.
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Age Calculator
Exact age in years, months and days, and the countdown to your next birthday.
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Pregnancy Due Date Calculator
Estimated due date, how many weeks pregnant you are and the trimester.
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GPA Calculator
Weighted and unweighted GPA on the US 4.0 scale.
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Fraction Calculator
Add, subtract, multiply and divide fractions and mixed numbers, with steps.
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Scientific Calculator
Order of operations, powers, roots, logs and trig in degrees or radians.
Pakistani and South Asian units
Converting marla, kanal, tola, seer or maund, or rupees to dollars, dirhams or riyals? See our guide to Pakistani units and converters.
Guides
The complete guide to unit conversion — exact factors, temperature formulas, US vs imperial traps and currency pitfalls.
How to use online calculators correctly — order of operations, VAT and sales tax, loan formulas, rounding and floating-point error.
About These Converters
Every conversion on pakmath.com is computed from exact, published conversion factors from NIST and the BIPM, the same figures used in engineering and scientific references. Each page explains the units, shows a worked example and cites its source. Content is reviewed by Dr. Muhammad Amjad Khadim, PhD Mathematics; see our editorial policy.
Frequently Asked Questions
Is pakmath.com free to use?
Yes. Every converter on pakmath.com is free, needs no signup and works on phones and computers.
How accurate are the conversions?
Fixed-unit conversions (length, weight, volume, area and so on) use exact, published factors such as 1 inch = 25.4 mm and 1 lb = 0.45359237 kg, taken from NIST and the BIPM. Results are shown to up to 10 decimal places, and every page is reviewed by Dr. Muhammad Amjad Khadim, PhD Mathematics.
Are there calculators as well as converters?
Yes. There are free calculators for mortgages, loans, compound interest, VAT, Canadian GST/HST, US sales tax, percentages, BMI, calories, dates, GPA, fractions and more, each with its formula and a worked example.
Where do the currency exchange rates come from?
Currency rates come from ExchangeRate-API's open data, updated daily and cached for up to 12 hours. They are mid-market reference rates, so banks and exchange companies will quote different buying and selling rates.
Which units can I convert?
Currency, length, weight and mass, temperature, volume, area, speed, time, pressure, angle, power and data storage, including Pakistani units such as marla, kanal, tola, seer and maund.
How do I convert from one unit to another?
Open the converter for your category, or use the search box above: type a number, choose the "from" and "to" units, and the result appears instantly. Each conversion also has its own page with a table, formula and FAQ.