How to Convert Units of Length, Weight and Temperature (Free)
Recipes in cups, distances in miles, weights in kilograms, temperatures in Fahrenheit — the world mixes metric and imperial units constantly, and converting between them in your head is hard. A unit converter does it instantly and accurately. This guide covers the most-needed conversions for length, weight and temperature, with the formulas behind them and how to convert for free.
📏 Try the Unit Converter now — freeOpen →Getting a conversion wrong can ruin a recipe, a measurement or a travel plan. Whether you're cooking from a foreign recipe, following build plans, checking your weight abroad, or reading a weather forecast in the other temperature scale, quick and correct conversions save time and mistakes.
The conversions you'll use most
- Length: 1 inch = 2.54 cm; 1 foot = 30.48 cm; 1 mile ≈ 1.609 km.
- Weight: 1 kilogram ≈ 2.205 pounds; 1 pound ≈ 0.454 kg; 1 ounce ≈ 28.35 g.
- Temperature: °C to °F = (°C × 9/5) + 32; °F to °C = (°F − 32) × 5/9.
- Volume: 1 litre ≈ 0.264 US gallons; 1 US cup ≈ 237 ml.
Temperature is the tricky one
Length and weight conversions are just multiplication, but temperature involves both a scale factor and an offset, which is why it trips people up. To go from Celsius to Fahrenheit you multiply by 9/5 and then add 32; to go back you subtract 32 first, then multiply by 5/9.
A quick sanity check: 0°C = 32°F (freezing), 100°C = 212°F (boiling), and the two scales meet at −40°, where −40°C equals −40°F. A converter handles the offset automatically so you never misplace the +32.
Step-by-step
Common mistakes to avoid
Pro tips
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. For example, 20°C × 9/5 + 32 = 68°F.
How many kilometers are in a mile?
About 1.609 km. So 5 miles ≈ 8 km.
How many pounds is a kilogram?
About 2.205 pounds. So 10 kg ≈ 22 lb.
Is the converter free and private?
Yes — free with no sign-up, and it runs in your browser, so nothing is uploaded.
Does it cover cooking measurements?
It covers length, weight and temperature; note that US and metric cups differ slightly in recipes.
From miles to kilometres, pounds to kilograms, and Celsius to Fahrenheit, a unit converter gives you the right answer instantly — no mental math, no misplaced +32. Pick the category, enter the value, and get an exact conversion, free in your browser.