Temperature converter
Convert temperatures between Celsius, Fahrenheit, and Kelvin instantly. Includes formulas and reference examples.
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Common temperature reference points
| Reference point | Celsius (°C) | Fahrenheit (°F) | Kelvin (K) |
|---|---|---|---|
| Absolute zero | -273.15 | -459.67 | 0 |
| Water freezing point | 0 | 32 | 273.15 |
| Room temperature | 20-22 | 68-71.6 | 293-295 |
| Human body temperature | 37 | 98.6 | 310.15 |
| Water boiling point | 100 | 212 | 373.15 |
| Oven (moderate) | 180 | 356 | 453.15 |
How to convert temperature units
Unlike most unit conversions, temperature scales are not related by simple multiplication because they each have a different zero point. The formulas below account for both the scale difference and the offset.
Celsius to Fahrenheit
°F = (°C × 9/5) + 32
Example: 25 °C = (25 × 9/5) + 32 = 77 °F
Fahrenheit to Celsius
°C = (°F - 32) × 5/9
Example: 98.6 °F = (98.6 - 32) × 5/9 = 37 °C
Celsius to Kelvin
K = °C + 273.15
Example: 100 °C = 100 + 273.15 = 373.15 K
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 (or 1.8) then add 32. For example, 20°C = (20 × 1.8) + 32 = 68°F. A quick mental shortcut: double the Celsius temperature and add 30 for a rough Fahrenheit estimate (20°C → 40 + 30 = 70°F, close to the exact 68°F).
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, 98.6°F = (98.6 − 32) × 5/9 = 66.6 × 0.5556 = 37°C. Key reference points: 32°F = 0°C (freezing), 72°F ≈ 22°C (room temperature), 98.6°F = 37°C (body temperature), 212°F = 100°C (boiling).
What temperature is the same in Celsius and Fahrenheit?
The two scales meet at exactly −40°. That is, −40°C = −40°F. This is a useful sanity check when converting very cold temperatures: if your result near −40 doesn't match between the two scales, the conversion is wrong.
How do I convert Celsius to Kelvin?
Add 273.15 to the Celsius value. For example, 100°C = 373.15 K, and 0°C = 273.15 K. Absolute zero (0 K) equals −273.15°C — the theoretical lowest possible temperature. Kelvin uses the same degree size as Celsius but starts at absolute zero, so there are no negative Kelvin values.
What is a normal body temperature in Celsius and Fahrenheit?
Normal human body temperature is 37°C (98.6°F). A fever is generally defined as above 38°C (100.4°F). These values are oral temperature readings; rectal and ear temperatures run slightly higher, and armpit temperatures slightly lower.
What are common oven temperatures in Celsius and Fahrenheit?
Common oven temperature conversions: 150°C = 300°F (low/slow), 180°C = 356°F (moderate, most baking), 200°C = 392°F (moderately hot), 220°C = 428°F (hot), 250°C = 482°F (very hot). Most baking recipes that originate in the US use Fahrenheit; European and UK recipes use Celsius.
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