The world runs on two measurement systems, and they collide constantly: American recipes in cups and Fahrenheit, European ones in grams and Celsius; road signs in miles in the US and UK, kilometers nearly everywhere else. This free unit converter bridges the gap instantly across length, weight, and temperature — no app install, no sign-up.
Length covers everything from millimeters to miles (handy for DIY projects, running distances, and travel planning). Weight spans grams to US tons, including stones for our UK visitors. Temperature handles the big three — Celsius, Fahrenheit, Kelvin — with the proper offset formulas, not just scaling.
Conversions happen live as you type, so you can slide through values and watch equivalents update in real time — perfect for cooking, homework, or comparing specs while shopping online.
How to use the Unit Converter
- Pick a category: Length, Weight, or Temperature.
- Choose the ‘from’ and ‘to’ units from the dropdowns.
- Type a value — the result converts live with every keystroke.
- Swap or change units freely; the conversion updates instantly.
Tips for accurate results
- Cooking across systems? 1 US cup ≈ 236.6 ml; weigh baking ingredients in grams for best results.
- Oven temperatures: 350°F = 175°C = gas mark 4 — the converter confirms it instantly.
- For running: a 10K is 6.21 miles; a marathon is 26.2 miles / 42.195 km.
- Body weight: 1 kg = 2.20462 lb — the exact factor this tool uses.
Why the US still uses imperial
The United States, Liberia, and Myanmar are the only countries not officially metric — a legacy of 19th-century industrial standards and the sheer cost of switching. The UK uses a hybrid (miles on roads, metric in shops). Science, medicine, and international trade run on metric, which is why converters like this remain essential.
Frequently asked questions
How do you convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. So 68°F = (68−32) × 5/9 = 20°C. The tool does this automatically.
How many pounds are in a kilogram?
Exactly 2.20462 lb per kg (1 lb = 0.45359237 kg by international agreement).
What is absolute zero in Celsius and Fahrenheit?
0 Kelvin = −273.15°C = −459.67°F — the coldest theoretically possible temperature.
Are US tons and metric tons the same?
No. A US (short) ton is 2,000 lb (907 kg); a metric tonne is 1,000 kg (2,204.6 lb). This converter uses US tons.