Metric Conversion Calculator & Unit Conversion Chart
Use these calculators and charts to convert common metric and U.S. customary units, including length, weight, temperature, area, volume, speed, pressure, power, time, fractions, and more.
Length & Distance
Convert inches, feet, yards, miles, centimeters, meters, and kilometers.
Weight & Mass
Convert ounces, pounds, grams, kilograms, tons, and metric tons.
Temperature
Convert Celsius, Fahrenheit, and Kelvin.
Volume
Convert teaspoons, tablespoons, cups, pints, quarts, gallons, liters, and milliliters.
Area
Convert square inches, square feet, square yards, acres, square meters, and hectares.
Speed
Convert miles per hour, kilometers per hour, meters per second, and knots.
Pressure
Convert psi, pascals, kilopascals, bars, atmospheres, and millimeters of mercury.
Power
Convert watts, kilowatts, horsepower, and other common power units.
Time
Convert seconds, minutes, hours, days, weeks, months, and years.
Fuel Economy
Convert miles per gallon, kilometers per liter, and liters per 100 kilometers.
Fractions & Decimals
Use a fraction-to-decimal chart for common math and measurement conversions.
Metric Conversion Chart
See common metric prefixes and conversion factors in one easy reference chart.
Most Common Conversions
Here are quick links for some of the most common measurement conversions. These will take you to the right calculator category.
How to Use the Science Made Simple Conversion Tools
Science Made Simple includes conversion calculators and charts for many common measurements, including length, weight, temperature, volume, area, speed, pressure, power, time, and more.
Start by choosing the type of measurement you want to convert. For example, if you want to convert inches and centimeters, choose Length & Distance. To convert pounds and kilograms, choose Weight & Mass. Then enter your number, select the units you want to convert from and to, and view the result instantly.
You can also explore the quick links above for common conversions or use our reference charts for help with metric prefixes, fractions, and other everyday measurement questions.
Understanding Measurement Conversions
Measurement conversions allow you to express the same amount using different units. For example, a distance can be measured in inches, feet, centimeters, meters, or miles, even though the actual length stays the same. Conversion calculators help you switch between units quickly and accurately.
Why Are There Different Measurement Systems?
Different parts of the world developed different systems of measurement. Most countries now use the metric system, which includes units such as meters, liters, and grams and is based on powers of ten. In the United States, many everyday measurements still use customary units such as inches, feet, pounds, gallons, and degrees Fahrenheit.
When Should You Use a Calculator or a Conversion Chart?
A conversion calculator is helpful when you need a fast, accurate answer or want to convert between many possible units. A conversion chart can be useful for learning, estimating, or quickly checking common metric prefixes and measurement relationships.
Frequently Asked Questions About Conversions
How do I convert centimeters to inches?
To convert centimeters to inches, divide the number of centimeters by 2.54. You can also use the Length & Distance conversion calculator for a quick answer.
How do I convert inches to centimeters?
To convert inches to centimeters, multiply the number of inches by 2.54. The Length & Distance conversion calculator can also do this instantly.
How do I convert kilograms to pounds?
To convert kilograms to pounds, multiply kilograms by about 2.205. You can also use the Weight & Mass conversion calculator for fast results.
How do I convert pounds to kilograms?
To convert pounds to kilograms, divide pounds by about 2.205. The Weight & Mass conversion calculator makes it easy to switch between units.
How do I convert Celsius to Fahrenheit?
To convert Celsius to Fahrenheit, multiply the Celsius temperature by 9/5 and then add 32. You can also use the Temperature conversion calculator for quick results.
What is a conversion factor?
A conversion factor is a number used to change one unit into another. For example, there are 2.54 centimeters in 1 inch, so 2.54 is a conversion factor between centimeters and inches.