Temperature Converter
Convert Celsius, Fahrenheit and Kelvin temperatures quickly. Useful for weather, science, travel, appliances and everyday UK-to-US temperature conversions.
Temperature converter calculator
Enter a temperature, choose the starting unit and choose the unit you want to convert to. The calculator shows the converted result and the formula used.
Popular temperature conversions
Use these quick buttons for common Celsius, Fahrenheit and Kelvin conversions.
How temperature conversion works
Temperature conversion is different from length or weight conversion because Celsius, Fahrenheit and Kelvin do not all start at the same zero point. That means you need a formula, not just a simple multiplication factor.
°F = (°C × 9/5) + 32
°C = (°F - 32) × 5/9
K = °C + 273.15For example, 20°C becomes 68°F because you multiply 20 by 9/5, then add 32.
Common temperature formulas
| Conversion | Formula | Example |
|---|---|---|
| Celsius to Fahrenheit | (°C × 9/5) + 32 | 20°C = 68°F |
| Fahrenheit to Celsius | (°F - 32) × 5/9 | 68°F = 20°C |
| Celsius to Kelvin | °C + 273.15 | 0°C = 273.15 K |
| Kelvin to Celsius | K - 273.15 | 293.15 K = 20°C |
| Fahrenheit to Kelvin | ((°F - 32) × 5/9) + 273.15 | 32°F = 273.15 K |
| Kelvin to Fahrenheit | ((K - 273.15) × 9/5) + 32 | 273.15 K = 32°F |
Useful temperature reference values
| Temperature | Celsius | Fahrenheit | Kelvin |
|---|---|---|---|
| Water freezes | 0°C | 32°F | 273.15 K |
| Room temperature | 20°C | 68°F | 293.15 K |
| Average body temperature | 37°C | 98.6°F | 310.15 K |
| Water boils | 100°C | 212°F | 373.15 K |
UK temperature notes
In the UK, everyday temperatures are normally shown in Celsius, especially weather forecasts, thermostats and food storage guidance. Fahrenheit is still useful when reading US recipes, appliance guides or older references.
- Weather and home: Celsius is the usual UK format.
- US content: Fahrenheit often appears in recipes, weather and appliance instructions.
- Science: Kelvin is commonly used for absolute temperature and scientific calculations.
- Cooking: use the Food & Cooking oven temperature converter for fan oven and gas mark conversions.
Rounding converted temperatures
For everyday use, one decimal place is usually enough. For weather, whole numbers are often fine. For science or technical work, keep more decimal places until the final answer.
FAQs
How do I convert Celsius to Fahrenheit?
Multiply Celsius by 9/5, then add 32. For example, 20°C is 68°F.
How do I convert Fahrenheit to Celsius?
Subtract 32 from Fahrenheit, then multiply by 5/9. For example, 68°F is 20°C.
What is 0°C in Fahrenheit?
0°C is 32°F. It is also 273.15 K.
What is Kelvin used for?
Kelvin is mainly used in science because it is an absolute temperature scale. 0 K is absolute zero.