Unit Converter

How to use the unit converter

Choose a category — length, weight, volume, temperature, and more — type a value, and select the units to convert between. The result appears instantly, and you can switch units without re-entering the number.

Metric vs. imperial, without the headache

The world uses two main systems, and mixing them is the usual source of errors: a recipe in grams, a tape measure in inches, a luggage scale in pounds. Converting to one system before you compare numbers removes the guesswork and the rounding surprises.

Tips for accurate conversions

Convert at the end, not at every step, to avoid compounding rounding errors. For temperature, remember that Celsius and Fahrenheit also have different zero points, so a simple ratio never works — always use the formula or this converter.

How unit conversion works

Every unit on this converter is defined relative to a single base unit for its category — meters for length, grams for mass, liters for volume, and so on. To convert a value, the tool first scales your input up to that base unit, then rescales it down to the target unit. That two-step math is why 1 mile always equals exactly 1,609.344 meters and 1 kilogram always equals 2.20462 pounds, no matter which direction you convert.

Temperature is the one exception. Because Celsius, Fahrenheit and Kelvin do not share a common zero point, they are converted with dedicated offset formulas rather than a simple ratio. The converter applies those formulas automatically the moment you switch to the Temperature tab, so you never have to think about the math yourself.

Common uses

• Cooking and baking — turn cups and tablespoons into milliliters, or ounces into grams, when a recipe uses the other system.
• Travel — convert miles to kilometers for road trips, or check how tall a 6-foot sign really is in meters.
• Fitness and health — switch body weight between pounds and kilograms, or track distances in kilometers vs miles.
• Home and DIY — convert room sizes from square feet to square meters, or compare fuel economy in mpg and L/100km.
• School and work — quick checks for science labs, shipping weights, and international specifications.

Frequently asked questions

Which units are supported?
The converter covers length, weight, temperature, volume, area and speed, with the most common metric, US customary and imperial units in each group.

Is the conversion accurate?
Yes. The factors are fixed international definitions (for example, 1 inch = 25.4 mm exactly), so results match any reference table.

Why does temperature need special handling?
Unlike length or weight, temperature scales start at different zeros, so a ratio alone would be wrong. The tool uses the correct offset formulas instead.

Can I use this offline?
Yes. All calculations run in your browser using the built-in values, so it works without an internet connection.

Conversion factors worth knowing

More questions, answered

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