About This Tool
Convert between Celsius, Fahrenheit, and Kelvin temperature scales instantly. Enter a temperature in any scale and see the equivalent values in all three. Includes common reference points (water freezing/boiling, body temperature, absolute zero) for quick context.
Frequently Asked Questions
- How do the conversion formulas work?
- °C to °F: multiply by 9/5, add 32. °F to °C: subtract 32, multiply by 5/9. °C to K: add 273.15. These are exact mathematical conversions — no rounding or approximation is involved.
- When should I use Kelvin?
- Kelvin is used in scientific and engineering contexts. It starts at absolute zero (0 K = -273.15°C) — the lowest possible temperature. There are no negative Kelvin values. It's the SI unit of temperature.
- What is -40 degrees special about?
- -40 is the unique point where Celsius and Fahrenheit scales intersect: -40°C = -40°F exactly. It's the only temperature with the same value in both scales.
- What is normal body temperature?
- Normal human body temperature is approximately 37°C / 98.6°F / 310.15 K. However, normal ranges vary from 36.1-37.2°C (97-99°F). The classic 98.6°F figure comes from a 19th-century German study and may be slightly high by modern measurements.