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Math Tool

Unit Converter 📏

Convert between different units of measurement. Perfect for science and math homework.

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📚 Common Conversions

• 1 inch = 2.54 centimeters
• 1 mile = 1.609 kilometers
• 1 pound = 0.454 kilograms
• 1 gallon = 3.785 liters

Convert between units of length, mass, volume, and temperature for homework and lab work, covering the metric and imperial systems that science courses require.

In science, the unit is part of the answer. A number without a unit is not a result, and carrying units through a calculation is one of the most reliable ways to catch an error before it reaches your conclusion.

How to use it

  1. Choose the quantity you are converting: length, mass, volume, or temperature.
  2. Select your starting and target units.
  3. Enter the value and read the converted result.

Units in scientific work

  • The SI base units are the metre, kilogram, second, ampere, kelvin, mole, and candela. Every other SI unit derives from these.
  • Prefixes scale by powers of ten: kilo is a thousand, centi a hundredth, milli a thousandth, and micro a millionth.
  • Kelvin and Celsius share a degree size, so a temperature difference is identical in both. Only the zero point differs, by 273.15.
  • Carry units through your working. If the units of your answer are wrong, the arithmetic is wrong too, which makes them a free error check.
  • Match significant figures to your least precise measurement. Reporting more digits than your data supports overstates precision.

Frequently asked questions

What is the difference between mass and weight?
Mass measures how much matter an object contains and is the same everywhere, measured in kilograms. Weight is the force gravity exerts on that mass, measured in newtons, and changes with location.
How do I convert Celsius to Kelvin?
Add 273.15. The degree size is identical in both scales, so only the zero point differs, which is why a temperature difference is the same number in either.
Why do units matter in a science answer?
Because the unit is part of the result, and carrying units through a calculation catches errors. If your working produces the wrong units, the method itself was wrong.