Free Unit Converter Online
Free Unit Converter Online is a free online tool by US AI. Length, weight, temperature. It runs completely in your browser — no signup, no download, works on mobile and desktop.
📖 How to use
- Enter a value, pick the unit to convert from and to, and see the result instantly across length, weight and temperature.
- Open the tool with the button above — it loads instantly.
- Your work stays on your device; nothing is uploaded anywhere.
✨ Why use this tool?
US AI's free unit converter online is fast, private and 100% free forever. Bookmark this page and share it with anyone who needs it.
⚡ Popular conversions
| Conversion | Factor | Example |
|---|---|---|
| Miles to kilometers | 1 mi = 1.60934 km | 5 mi = 8.0467 km |
| Kilometers to miles | 1 km = 0.621371 mi | 10 km = 6.21371 mi |
| Feet to meters | 1 ft = 0.3048 m | 6 ft = 1.8288 m |
| Inches to feet | 12 in = 1 ft | 36 in = 3 ft |
| Yards to meters | 1 yd = 0.9144 m | 100 yd = 91.44 m |
| Kilograms to pounds | 1 kg = 2.20462 lb | 70 kg = 154.323 lb |
| Pounds to kilograms | 1 lb = 0.453592 kg | 150 lb = 68.0388 kg |
| Ounces to grams | 1 oz = 28.3495 g | 16 oz = 453.592 g |
| Celsius to Fahrenheit | °F = (°C × 9/5) + 32 | 25°C = 77°F |
| Fahrenheit to Celsius | °C = (°F − 32) × 5/9 | 98.6°F = 37°C |
❓ Frequently asked questions
Which unit conversions are supported?
Length, weight, and temperature — covering metric, US customary, and imperial units.
How do I convert Celsius to Fahrenheit?
Select temperature, enter the Celsius value, and the tool applies F = (C x 9/5) + 32 instantly — no formula to memorize.
Does the unit converter work offline?
The converter itself runs fully in your browser, so once the page has loaded, conversions work without an internet connection.
How many miles are in a kilometer?
1 km = 0.621371 mi, and 1 mi = 1.60934 km. Type the value in the tool above to convert any distance instantly.
How do I convert kilograms to pounds?
Multiply kilograms by 2.20462 to get pounds (1 kg = 2.20462 lb). For pounds to kilograms, multiply by 0.453592 instead.
How do I convert Fahrenheit to Celsius?
Use °C = (°F − 32) × 5/9. For example, 98.6°F = 37°C. To go the other way, use °F = (°C × 9/5) + 32.
Which temperature units are supported?
Celsius (°C), Fahrenheit (°F) and Kelvin (K) — pick any two and the converter handles the math for you.