Free Celsius to Fahrenheit Converter

Convert temperatures between Celsius and Fahrenheit. Type in either box for an instant result, and check the table for everyday reference points.

Celsius (°C)

Fahrenheit (°F)

Common values

Celsius	Fahrenheit
-40 °C	-40 °F
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

Quick answer

To convert Celsius to Fahrenheit, multiply by 9/5 (1.8) and add 32: °F = °C × 9/5 + 32. For example, 20 °C = 68 °F. To convert Fahrenheit to Celsius, subtract 32 first, then multiply by 5/9.

Formula & method

Celsius to Fahrenheit

°F = °C × 9/5 + 32

°C — temperature in Celsius
9/5 — 1.8, the ratio of a Fahrenheit to a Celsius degree
32 — the freezing point of water in Fahrenheit

Fahrenheit to Celsius

°C = (°F − 32) × 5/9

Examples

Example 1: Freezing point of water

Input: 0 °C
Result: 32 °F
Why: 0 × 9/5 + 32 = 32.

Example 2: Boiling point of water

Input: 100 °C
Result: 212 °F
Why: 100 × 9/5 + 32 = 180 + 32 = 212.

Example 3: Body temperature

Input: 37 °C
Result: 98.6 °F
Why: 37 × 9/5 + 32 = 66.6 + 32 = 98.6.

When to use this tool

Reading a weather forecast, oven setting, or thermostat in the other unit.
Converting a body temperature reading.
Following a recipe or instructions written for a different region.

Common mistakes

Adding 32 before multiplying. Multiply by 9/5 first, then add 32.
Using 2 instead of 1.8 for the ratio. The factor is 9/5 = 1.8 exactly.
Forgetting that −40 is the one temperature that reads the same in both scales.

Frequently asked questions

＋ How do I convert Celsius to Fahrenheit?

Multiply the Celsius value by 9/5 (which is 1.8) and add 32. For example, 25 °C × 1.8 = 45, plus 32 = 77 °F.

＋ How do I convert Fahrenheit to Celsius?

Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, (212 − 32) × 5/9 = 100 °C.

＋ What is a quick mental estimate?

Double the Celsius value and add 30 for a rough Fahrenheit estimate. It’s close near room temperature but drifts at extremes.

＋ At what temperature are Celsius and Fahrenheit equal?

At −40 degrees. −40 °C equals −40 °F — the only point where the two scales meet.

＋ What is normal body temperature in each scale?

About 37 °C, which is 98.6 °F, though normal varies a little from person to person.

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Last updated: 2026-06-05How we calculate Report a correction Disclaimer

Provided “as is” for general information only — results may be inaccurate, so verify before you rely on them. No warranty; use at your own risk.