Unit Converter
Convert between metric and imperial units for length, weight, temperature, area, and volume in one tool.
Our free Unit Converter is an all-in-one tool for converting between metric and imperial units across five measurement categories: length, weight, temperature, area, and volume. Instead of searching for separate converters, do all your conversions… Use the fields above to enter values and get an instant answer. All processing happens on your device.
About This Calculator
Our free Unit Converter is an all-in-one tool for converting between metric and imperial units across five measurement categories: length, weight, temperature, area, and volume. Instead of searching for separate converters, do all your conversions in one place. Convert centimeters to inches, kilograms to pounds, Celsius to Fahrenheit, square meters to square feet, or liters to gallons — all instantly. Ideal for students solving physics problems, cooks adapting international recipes, travelers comparing distances, engineers working across measurement systems, and anyone who encounters unfamiliar units in daily life.
How It Works
Select a measurement category (length, weight, temperature, area, or volume), enter the value, pick the source unit, and pick the target unit. The converter applies the standard conversion factor and displays the result immediately. Length and weight use simple multiplication factors (e.g., 1 inch = 2.54 cm). Temperature uses formulas (e.g., F = C x 9/5 + 32). Area and volume factors are the squares and cubes of their linear equivalents. All factors follow international standards (NIST/SI) for accuracy.
How to Use
- Enter your values in the calculator fields above
- Click the calculate button or let the calculator auto-update
- Review your results instantly
- Adjust values as needed to see different scenarios
Frequently Asked Questions
What units does this converter support?
Length: millimeters, centimeters, meters, kilometers, inches, feet, yards, miles. Weight: milligrams, grams, kilograms, metric tons, ounces, pounds, stones. Temperature: Celsius, Fahrenheit, Kelvin. Area: square centimeters/meters/kilometers, square inches/feet/yards, acres, hectares. Volume: milliliters, liters, cubic meters, fluid ounces, cups, pints, quarts, gallons.
What is the difference between metric and imperial systems?
The metric system (SI) uses base-10 multiples (1 km = 1,000 m, 1 kg = 1,000 g) and is used by most of the world. The imperial/US customary system uses non-decimal relationships (1 foot = 12 inches, 1 pound = 16 ounces) and is primarily used in the United States, Liberia, and Myanmar.
Are the conversions exact or approximate?
Most conversions are exact by definition (1 inch is defined as exactly 2.54 cm, 1 pound as exactly 0.45359237 kg). Temperature conversions and a few others involve irrational numbers and are rounded to several decimal places, which is more than sufficient for any practical use.
Can I convert between units in the same system?
Yes. You can convert meters to kilometers (metric-to-metric), feet to miles (imperial-to-imperial), or across systems (meters to feet). The converter handles all combinations within each category.
Is this tool free and private?
Yes. All conversions happen locally in your browser. No data is sent to any server, no account is needed, and there are no usage limits.
Why Use Our Free Unit Converter Online?
Our Unit Converter uses standard formulas and works in your browser—no install or sign-up. Use it for homework, travel, or everyday conversions. Results are instant and we don't collect your inputs. Explore our other math and unit converters from the link below.