Universal Unit Converter
Convert between major units of length, mass and area. Simple interface with instant results.
Category
Conversion
Everything you need to know about unit conversion
Why use an online unit converter?
Measurement systems vary by country: the metric system is used in most of the world, while the United States, the United Kingdom, and a few other countries use the imperial system. A reliable converter prevents costly calculation errors.
Whether you are a student, engineer, cook, or DIY enthusiast, unit conversion is a daily task. A free, instant online tool saves you valuable time compared to manual calculations.
Conversion errors can have serious consequences: in 1999, NASA's Mars Climate Orbiter was lost due to a mix-up between metric and imperial units. An automatic converter eliminates this risk.
Common use cases
- International travel
- Quickly convert miles to kilometers, pounds to kilograms, or square feet to square meters to understand distances, weights, and areas mentioned in countries using the imperial system.
- Home improvement and DIY
- Convert measurements from plans and materials between centimeters, inches, feet, and meters to adapt instructions or dimensions from international sources.
- Science and education
- Perform precise conversions between milligrams, grams, kilograms, and metric tons for your physics, chemistry, or biology exercises, with results displayed in scientific notation when needed.
- Real estate and land
- Convert areas between square meters, hectares, acres, and square feet to compare properties whose sizes are expressed in different units depending on the country.
How to use the unit converter?
First choose the desired measurement category: length, mass, or area. Each category offers the most common units from both the metric and imperial systems.
Enter the value to convert, then select the source unit and target unit. The result is displayed instantly with 10 significant digits of precision.
Check the 'All conversions' table to see the value converted to every unit in the category at a glance. Use the swap button to quickly reverse the units.
Frequently asked questions about unit conversion
- What is the difference between the metric and imperial systems?
- The metric system (SI) uses units based on powers of 10: meter, kilogram, etc. The imperial system uses units like inches, feet, pounds, and miles. The metric system is used by nearly all countries, except the United States which primarily uses the imperial system.
- Are the conversions exact or rounded?
- This tool uses official conversion factors with 10 significant digits of precision. For very large or very small numbers, the result is displayed in scientific notation to avoid any loss of precision.
- What is the relationship between hectares and square meters?
- One hectare equals exactly 10,000 square meters (100 m x 100 m). It is a unit commonly used to measure agricultural land and large plots of land.
- How do I convert inches to centimeters?
- One inch equals exactly 2.54 centimeters. To convert inches to centimeters, multiply the value in inches by 2.54. For example, 10 inches = 25.4 cm. Our tool performs this calculation automatically.
- Why do some countries still use the imperial system?
- The United States, Liberia, and Myanmar are the only countries that have not officially adopted the metric system as their primary system. In the US, conversion attempts have been made but met with cultural resistance and the cost of transitioning industry.