Temperature Converter
Convert between Celsius (°C), Fahrenheit (°F), and Kelvin (K) instantly.
Instant 3-Way Temperature Converter
Type in any box to instantly convert between Celsius (°C), Fahrenheit (°F), and Kelvin (K).
Water Freezes at 0°C • Boils at 100°C
Water Freezes at 32°F • Boils at 212°F
Absolute Zero at 0 K • Freezes at 273.15 K
°F = (25°C × 9/5) + 32 = 77°F
K = 25°C + 273.15 = 298.15 K
Understanding Temperature Scales: Celsius, Fahrenheit & Kelvin
Temperature measures the average kinetic energy of the molecules in a substance. Three primary temperature scales are widely used across the world today:
- Celsius (°C): Devised by Swedish astronomer Anders Celsius in 1742, the Celsius scale sets 0°C at the freezing point of pure water and 100°C at its boiling point at standard atmospheric pressure. It is used internationally by virtually all countries and in scientific weather measurement.
- Fahrenheit (°F): Proposed by physicist Daniel Gabriel Fahrenheit in 1724, this scale is predominantly used in the United States, Bahamas, Cayman Islands, and Belize. On the Fahrenheit scale, pure water freezes at 32°F and boils at 212°F, dividing the interval into 180 degrees.
- Kelvin (K): Named after Lord Kelvin in 1848, Kelvin is the SI base unit of thermodynamic temperature. It starts at Absolute Zero (0 K), where all thermal motion of molecules stops completely. Kelvin does not use the degree symbol (°).
Standard Temperature Conversion Formulas
Celsius to Fahrenheit:
°F = (°C × 9/5) + 32
Example: (20 × 1.8) + 32 = 68°F
Fahrenheit to Celsius:
°C = (°F − 32) × 5/9
Example: (68 − 32) × 0.5556 = 20°C
Celsius to Kelvin:
K = °C + 273.15
Example: 25 + 273.15 = 298.15 K
Kelvin to Celsius:
°C = K − 273.15
Example: 300 − 273.15 = 26.85°C
Common Reference Temperature Table
| Physical State / Milestone | Celsius (°C) | Fahrenheit (°F) | Kelvin (K) |
|---|---|---|---|
| Absolute Zero | -273.15 °C | -459.67 °F | 0 K |
| Equal Point of Scales | -40.00 °C | -40.00 °F | 233.15 K |
| Water Freezing Point | 0.00 °C | 32.00 °F | 273.15 K |
| Comfortable Room Temp | 20.00 °C | 68.00 °F | 293.15 K |
| Average Human Body Temp | 37.00 °C | 98.60 °F | 310.15 K |
| Water Boiling Point | 100.00 °C | 212.00 °F | 373.15 K |