🌡️ Temperature Converter
Convert between Celsius (°C), Fahrenheit (°F), and Kelvin (K) instantly. Results update as you type.
All Scales at a Glance
Temperature Conversion Formulas
°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
K = °C + 273.15
°C = (°F − 32) × 5/9
K = °C + 273.15
Understanding Temperature Scales
Celsius (°C) — Used by most countries. Water freezes at 0°C and boils at 100°C at standard atmospheric pressure. Named after Swedish astronomer Anders Celsius.
Fahrenheit (°F) — Used primarily in the United States. Water freezes at 32°F and boils at 212°F. Named after German-Polish physicist Daniel Gabriel Fahrenheit.
Kelvin (K) — The SI unit of temperature used in science. Starts at absolute zero (−273.15°C). The degree symbol is not used — it's simply "Kelvin" or "K". Named after Lord Kelvin.
Common Temperature References
| Description | °C | °F | K |
|---|---|---|---|
| Absolute Zero | −273.15 | −459.67 | 0 |
| Water Freezes | 0 | 32 | 273.15 |
| Room Temperature | 20–22 | 68–72 | 293–295 |
| Human Body | 37 | 98.6 | 310.15 |
| Water Boils | 100 | 212 | 373.15 |
| Oven (Baking) | 180 | 356 | 453.15 |
| C and F Equal | −40 | −40 | 233.15 |
Quick Mental Conversion Tips
- °C to °F rough estimate: Double the Celsius value and add 30. Example: 25°C ≈ 50 + 30 = 80°F (actual: 77°F).
- °F to °C rough estimate: Subtract 30, then halve. Example: 80°F ≈ (80−30)/2 = 25°C (actual: 26.7°C).
- Key anchors: 0°C = 32°F, 10°C = 50°F, 20°C = 68°F, 30°C = 86°F, 37°C = 98.6°F, 100°C = 212°F.
Frequently Asked Questions
Multiply the Celsius temperature by 9/5 (or 1.8), then add 32. For example: 25°C × 1.8 + 32 = 77°F. The formula is °F = (°C × 9/5) + 32.
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. For example: 77°F − 32 = 45, then 45 × 5/9 = 25°C. The formula is °C = (°F − 32) × 5/9.
Absolute zero is 0 Kelvin (−273.15°C or −459.67°F). It represents the theoretical lowest possible temperature where all thermal motion of particles ceases. No physical system can reach absolute zero, though scientists have come very close in laboratory conditions.
−40° is the same in both scales. If you set °F = °C in the formula °F = (°C × 9/5) + 32 and solve, you get −40. This is the only temperature where the two scales intersect.
The Fahrenheit scale was widely adopted in English-speaking countries in the 18th century. While most nations switched to Celsius during metrication in the 20th century, the US retained Fahrenheit for everyday weather and cooking. Fahrenheit does offer finer granularity for weather temperatures (the 0-100°F range roughly maps to the range of outdoor temperatures in temperate climates).