Free Temperature Converter - Celsius Fahrenheit Kelvin
Convert temperatures between Celsius, Fahrenheit, and Kelvin instantly with our free online temperature converter. Essential for cooking, science, weather, and international travel.
About Temperature Units
Temperature can be measured in different scales depending on your location and use case. Our converter supports the three most common temperature scales used worldwide.
Celsius (°C)
The metric standard used by most countries worldwide. Water freezes at 0°C and boils at 100°C at standard atmospheric pressure.
Fahrenheit (°F)
Used primarily in the United States and some Caribbean nations. Water freezes at 32°F and boils at 212°F.
Kelvin (K)
The SI base unit for temperature, used in science. Zero Kelvin (0K) is absolute zero, the lowest possible temperature.
Features of Our Temperature Converter
- Three unit support - Celsius, Fahrenheit, and Kelvin
- Bidirectional conversion - Convert from any unit to any other
- Swap button - Quickly reverse conversion direction
- Precise decimals - Accurate to hundredths of a degree
- Common temperatures reference - Quick reference guide
- Mobile friendly - Works on any device
Temperature Conversion Formulas
Celsius to Fahrenheit
°F = (°C × 9/5) + 32
Fahrenheit to Celsius
°C = (°F - 32) × 5/9
Celsius to Kelvin
K = °C + 273.15
Kelvin to Celsius
°C = K - 273.15
Common Temperature Reference Points
| Description | Celsius | Fahrenheit | Kelvin |
|---|---|---|---|
| Absolute Zero | -273.15°C | -459.67°F | 0K |
| Water Freezes | 0°C | 32°F | 273.15K |
| Room Temperature | 20°C | 68°F | 293.15K |
| Body Temperature | 37°C | 98.6°F | 310.15K |
| Water Boils | 100°C | 212°F | 373.15K |
How to Use the Temperature Converter
- Select your source unit (Celsius, Fahrenheit, or Kelvin)
- Select your target unit
- Enter the temperature value
- View the converted result instantly
- Use the swap button to reverse the conversion
FAQs About Temperature Conversion
Why are there different temperature scales?
Different scales were developed independently. Fahrenheit (1724) was created by Daniel Fahrenheit, Celsius (1742) by Anders Celsius, and Kelvin (1848) by Lord Kelvin for scientific purposes.
When do Celsius and Fahrenheit equal each other?
At -40 degrees, Celsius and Fahrenheit are the same: -40°C = -40°F.
Why is Kelvin used in science?
Kelvin starts at absolute zero with no negative values, making it ideal for scientific calculations involving thermodynamics.
How do I convert temperature in my head?
For rough Celsius to Fahrenheit: double the Celsius, subtract 10%, and add 32. Example: 20°C → 40, 40-4=36, 36+32=68°F.
Use Cases for Temperature Conversion
- Cooking recipes - Convert between metric and US measurements
- Weather - Understand temperatures when traveling abroad
- Science projects - Convert between Kelvin and Celsius
- Fever checking - Convert body temperature readings
- HVAC settings - Set thermostats correctly
Why Use Our Temperature Converter?
- Free and fast - No registration needed
- Accurate - Precise to decimal places
- All three scales - Celsius, Fahrenheit, and Kelvin
- Easy to use - Simple, intuitive interface
- Works offline - Use without internet connection