Convert Any Measurement in Seconds
Need to convert centimeters to inches or kilograms to pounds? This free converter gives you an instant, accurate answer. It also handles Celsius to Fahrenheit and US dollars to euros. You don't need a spreadsheet or a formula. The tool covers length, weight, temperature, area, volume, speed, data storage, energy, pressure and currency, and it works on phones as well as desktops.
How to Use the Converter
- Choose a category from the list, or search for a unit by name.
- Type the value you want to convert in the From box.
- Pick the starting unit and the target unit. Use the swap button to reverse them.
- Read the result, adjust the precision, and copy or share it if you need to.
Why Use an Online Unit Converter?
Conversion mistakes are common. A misplaced decimal can ruin a recipe or a measurement. It can also throw off a shipping weight. This tool applies exact conversion factors every time. You can adjust the precision and check the conversion table for reference.
Metric vs. Imperial Units
Most of the world uses the metric system, which is built on powers of ten. The United States relies mainly on US customary units, and the United Kingdom still uses imperial units for things like miles and pints. That mix is why so many people need to convert between the two. The table shows a few reference points.
| Metric | Imperial / US customary |
|---|---|
| 1 inch | 2.54 centimeters (exact) |
| 1 mile | 1.609344 kilometers (exact) |
| 1 pound | 0.45359237 kilograms (exact) |
| 1 US gallon | 3.785 liters (approx.) |
Length and Distance
Convert millimeters, centimeters, meters and kilometers. You can also use inches, feet, yards and miles. Nautical miles and scientific units are included. Popular searches like cm to inches and miles to km get an instant answer. The formula is shown next to the result. It suits construction, travel planning, sewing and homework.
Weight and Mass
Kilograms to pounds is one of the most searched conversions online. Fitness tracking, shipping and cooking all rely on it. This converter supports milligrams, grams, kilograms, tonnes, ounces, pounds and stones. Results are precise, with no rounding surprises.
Temperature
Switch between Celsius, Fahrenheit and Kelvin. Use it to check an oven setting such as 350 F in Celsius. You can also convert a weather forecast from another country. The tool applies the correct offset formulas automatically.
Area, Volume and Speed
Convert square meters to square feet or acres to hectares. Switch liters to gallons or milliliters to fluid ounces. Change km/h to mph or meters per second to knots. These are handy for real estate, cooking, cars and shipping paperwork.
Data, Energy and Pressure
The data converter covers bytes through terabytes. It clears up the difference between binary and decimal units. The energy converter handles joules, calories, kilowatt-hours and BTU. The pressure converter covers pascals, bar, PSI and atmospheres.
Live Currency Rates
Convert USD, EUR, GBP, JPY and dozens of other currencies. Tap refresh to load the latest rate. The exact rate is always shown below the result. Rates are indicative, so check with your bank before a large transfer.
Tips for Accurate Conversions
- Confirm which unit variant you need. US and imperial gallons and pints differ.
- Use more decimal places for engineering or science work, and fewer for everyday use.
- Convert temperatures with the converter, not by scaling. Celsius and Fahrenheit have different zero points.
- Convert first, round last. Rounding early compounds errors across several steps.
Free and Easy to Use
The converter is free and needs no sign-up. Results update as you type. Search for a unit, revisit your history, or save favorites. A full conversion table sits under every category.
Frequently Asked Questions
How do I convert centimeters to inches?
Divide the centimeter value by 2.54. Or pick Centimeter and Inch in the converter above.
What is the formula for Celsius to Fahrenheit?
Multiply Celsius by 9/5, then add 32. The converter does this for you.
How many pounds are in a kilogram?
One kilogram is about 2.20462 pounds.
How many feet are in a meter?
One meter is about 3.28084 feet. To go the other way, one foot is exactly 0.3048 meters.
What is the difference between metric and imperial units?
Metric units, such as meters and kilograms, are based on powers of ten. Imperial units, such as feet and pounds, use historical ratios like 12 inches to a foot. The converter moves between both systems.
Are US and imperial gallons the same?
No. A US gallon is about 3.785 liters and an imperial gallon is about 4.546 liters. Check which gallon a conversion uses, especially for fuel and recipes.
Is this unit converter free?
Yes. Every category is free, and no account is required.
Sources and References
Our conversion factors follow international standards. Learn more from these sources: