Quick answer: °F = °C × 9/5 + 32, so a Gulf summer day of 45 °C is 45 × 1.8 + 32 = 113 °F; and °C = (°F − 32) × 5/9.
How it's calculated
Celsius to Fahrenheit: multiply by 9/5 (1.8) and add 32. Fahrenheit to Celsius: subtract 32 and multiply by 5/9. The two scales meet at −40, where −40 °C = −40 °F.
Kelvin is the SI unit of temperature: K = °C + 273.15, and 0 K is absolute zero, the lowest possible temperature. Rankine is the Fahrenheit-sized absolute scale: °R = K × 9/5.
Temperature differences convert without the offset: a rise of 10 °C is a rise of 18 °F and of 10 K.
Worked examples
- Summer heat: 45 °C = 113 °F
- Body temperature: 98.6 °F = 37 °C
- Oven setting: 350 °F = 176.66667 °C
Common temperatures
| From | To |
|---|---|
| -40 °C | -40 °F |
| 0 °C | 32 °F |
| 20 °C | 68 °F |
| 25 °C | 77 °F |
| 37 °C | 98.6 °F |
| 45 °C | 113 °F |
| 50 °C | 122 °F |
| 100 °C | 212 °F |
| 180 °C | 356 °F |
| 0 °C | 273.15 K |
Frequently asked questions
How do I convert Celsius to Fahrenheit in my head?
Double the Celsius figure and add 30 for a rough answer (45 °C → about 120 °F; exact is 113 °F). For the exact value multiply by 1.8 and add 32.
What is normal body temperature in Fahrenheit?
About 37 °C, which is 98.6 °F. Normal readings vary by about half a degree Celsius during the day.
Can a temperature in kelvin be negative?
No. 0 K is absolute zero (−273.15 °C), so kelvin values are never negative, and this converter rejects lower values.
What is 45 °C in Fahrenheit?
113 °F, which is nothing unusual for a July afternoon in Riyadh, Dubai or Kuwait.
What is 100 °F in Celsius?
About 37.8 °C.
What temperature should I set the AC to?
Most people are comfortable at 22 to 24 °C (72 to 75 °F). Every degree warmer saves electricity, so go as high as you can still sleep.