Instant converter
Celsius to Fahrenheit
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Celsius
25.0 °C
Fahrenheit
77.0 °F
Kelvin
298.1 K
Formula · worked example
°F = 25 × 9/5 + 32 = 77.0
Celsius to Fahrenheit formula
The exact conversion is °F = °C × 9/5 + 32 (or °F = °C × 1.8 + 32). Multiply by nine-fifths to stretch the Celsius degree size onto the Fahrenheit scale, then shift by 32 so water’s freezing point lines up at 32°F.
Reverse it with °C = (°F − 32) × 5/9. Try Fahrenheit to Celsius for the opposite direction, or Celsius to Kelvin for absolute temperature.
Quick mental-math trick
For weather estimates: double Celsius and add 30. Example: 20°C → 40 + 30 = 70°F (true value is 68°F). Close enough for “do I need a jacket?” decisions. For cooking, fever checks, and anything precise, use the full ×1.8 + 32 formula above — or this converter.
Common conversions
Body temp, oven settings, and everyday weather — with links to dedicated pages.
| Context | Celsius | Fahrenheit |
|---|---|---|
| Freezing (water) | 0°C | 32°F |
| Cool room | 15°C | 59°F |
| Room temperature | 20°C | 68°F |
| Comfortable room | 22°C | 71.6°F |
| Warm day | 25°C | 77°F |
| Hot day | 30°C | 86°F |
| Body temperature | 37°C | 98.6°F |
| Low oven | 150°C | 302°F |
| Moderate oven | 180°C | 356°F |
| Standard bake | 190°C | 374°F |
| Hot oven | 200°C | 392°F |
| Boiling (water) | 100°C | 212°F |
See also the full oven temperature conversion chart and body temperature page.
Frequently asked questions
Quick answers for the searches people make most.
How do you convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 (or 1.8), then add 32. Formula: °F = °C × 9/5 + 32. Example: 25°C × 1.8 + 32 = 77°F.
How do you convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. Formula: °C = (°F − 32) × 5/9. Example: (77 − 32) × 5/9 = 25°C.
What is 0°C in Fahrenheit?
0°C equals 32°F — the freezing point of water at standard pressure.
What is 100°C in Fahrenheit?
100°C equals 212°F — the boiling point of water at standard atmospheric pressure.
What is normal body temperature in Celsius and Fahrenheit?
A commonly cited average oral body temperature is 37°C or 98.6°F. Healthy baselines usually fall roughly between 36.1–37.2°C (97–99°F).
Is there a quick mental math trick for Celsius to Fahrenheit?
Double the Celsius value and add 30 for a fast estimate (accurate within a few degrees for everyday weather). For precision, use ×1.8 + 32.
What is -40°C in Fahrenheit?
-40°C equals -40°F. It is the only temperature where the Celsius and Fahrenheit scales show the same number.
How do you convert Celsius to Kelvin?
Add 273.15 to the Celsius temperature. Formula: K = °C + 273.15. Example: 25°C = 298.15 K.
Recommended thermometers
Handy tools if you convert temperatures often. Affiliate links — we may earn a commission (marked TODO until real tags are added).