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Celsius to Fahrenheit (°C to °F)
Convert celsiuss to fahrenheits instantly. The formula is °f = °c × 9⁄5 + 32 — multiply by 9/5 (1.8) and add 32 — 20 °C room temperature is 68 °F, 37 °C body temperature is 98.6 °F. Everything is computed locally in your browser; nothing is uploaded.
How to convert °C to °F
The exact conversion factor between celsiuss and fahrenheits gives the formula °F = °C × 9⁄5 + 32. Multiply by 9/5 (1.8) and add 32 — 20 °C room temperature is 68 °F, 37 °C body temperature is 98.6 °F.
For a rough mental estimate, remember that 1 °C = 33.8 °F. To go the other way, see the fahrenheit to celsius converter — it uses the reciprocal factor.
Worked examples
Example: convert 0 °C to °F. Apply the formula — °f = °c × 9⁄5 + 32 — and you get 32 °F. Reverse-check it by using the fahrenheit to celsius to come back to 0 °C; if you do not land on the original number, a factor was inverted.
Example: convert 100 °C to °F. Apply the formula — °f = °c × 9⁄5 + 32 — and you get 212 °F. Reverse-check it by using the fahrenheit to celsius to come back to 100 °C; if you do not land on the original number, a factor was inverted.
Where the factor comes from
Celsius and Fahrenheit are not related by a simple factor because their zero points differ: 0 °C is the freezing point of water, while 0 °F was set to the freezing point of a salt solution. The scales meet at −40 degrees (−40 °C = −40 °F), which makes −40 the fastest sanity check in temperature conversion. The Fahrenheit degree is also smaller — exactly 5⁄9 of a Celsius degree — which is why the formula multiplies by 9⁄5 before adding 32.Common mistakes
Adding 32 before multiplying. Order matters: multiply by 9⁄5 first, then add 32. Doing it backwards inflates the result by nearly a factor of two at room temperatures.
Treating °C and K with the same formula. Kelvin has no offset: K = °C + 273.15, no 9⁄5 factor. The formulas on this page apply only to the Celsius–Fahrenheit pair.
Trusting body-temperature folklore. 98.6 °F is a rounded 19th-century average; modern references put normal body temperature closer to 97.5–99 °F depending on the person and the time of day.
Quick mental shortcuts
Mental shortcuts: °C → °F ≈ double and add 30 (20 °C → 70 °F, true value 68); °F → °C ≈ subtract 30 and halve (70 °F → 20 °C). Exact only at −40°, but useful within ±2° for weather.
Common °C to °F conversions
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| -40 | -40 |
| 0 | 32 |
| 20 | 68 |
| 37 | 98.6 |
| 100 | 212 |
FAQ
How do I convert °C to °F?
°F = °C × 9⁄5 + 32. Multiply by 9/5 (1.8) and add 32 — 20 °C room temperature is 68 °F, 37 °C body temperature is 98.6 °F.
What is 0 °C in °F?
0 °C equals 32 °F. Use the converter above for any value.
How do I convert °F back to °C?
Use the reverse conversion — see our fahrenheit to celsius converter. The calculator above also shows the reciprocal rate.
Is the °C-to-°F conversion exact?
The formulas are exact mathematical definitions of the scales; everyday readings are rounded to one or two decimals.
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