Celsius to Fahrenheit Converter

Convert Celsius to Fahrenheit instantly — °F = °C × 9/5 + 32

Convert

°C

°F

20 °C =

68 °F

Quick Reference

-40 °C-40 °F

0 °C32 °F

10 °C50 °F

20 °C68 °F

25 °C77 °F

30 °C86 °F

37 °C98.6 °F

100 °C212 °F

All utility & math

Quick summary

To convert Celsius to Fahrenheit, multiply by 9/5 (1.8) and add 32. So 0 °C = 32 °F, 20 °C = 68 °F, 37 °C = 98.6 °F, and 100 °C = 212 °F. To go back, subtract 32 and multiply by 5/9 — 72 °F is 22.22 °C. The two scales meet at −40°, which reads the same on both. Use swap to reverse.

Reviewed by Simple Calculators TeamLast reviewed July 18, 2026

How to use this calculator

Type the temperature in Celsius into the °C field — negative values work too.
Read the result in the °F field and in the large result line below it (rounded to two decimal places).
To convert Fahrenheit to Celsius, press the Swap units button between the fields and enter the value in °F.
Check the Quick Reference table for common temperatures, from −40 °C to 100 °C.
Press Reset to return to the default of 20 °C.

Temperature Conversion Formulas

Celsius to Fahrenheit

T_F = T_C \times \frac{9}{5} + 32

T_C: Temperature in degrees Celsius (°C)
T_F: Temperature in degrees Fahrenheit (°F)
9/5: Ratio of degree sizes (1.8 °F per °C)

Worked example

Convert 37 °C to Fahrenheit

Given: T_C = 37 °C
Calculation: $T_F = 37 \times 1.8 + 32 = 66.6 + 32$
Result: 37 °C = 98.6 °F

Fahrenheit to Celsius

T_C = (T_F - 32) \times \frac{5}{9}

T_F: Temperature in degrees Fahrenheit (°F)
T_C: Temperature in degrees Celsius (°C)

Worked example

Convert 72 °F to Celsius

Given: T_F = 72 °F
Calculation: $T_C = (72 - 32) \times \frac{5}{9} = \frac{200}{9}$
Result: 72 °F = 22.22 °C

Frequently asked questions

How do I convert Celsius to Fahrenheit?

Multiply the Celsius temperature by 9/5 (1.8), then add 32. For example, 25 °C × 1.8 + 32 = 77 °F, and 30 °C × 1.8 + 32 = 86 °F. To convert Fahrenheit to Celsius, reverse the steps: subtract 32 first, then multiply by 5/9. The converter applies the exact formula and rounds the display to two decimals.

How do I convert Fahrenheit to Celsius?

Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. For example, (72 − 32) × 5/9 = 22.22 °C, and a 350 °F oven is (350 − 32) × 5/9 = 176.67 °C. In the converter, press the swap button so the input reads °F, then type the Fahrenheit value to see Celsius.

What is 37 °C in Fahrenheit?

37 °C is exactly 98.6 °F (37 × 1.8 + 32). It's the figure most often quoted as normal human body temperature, which is why this conversion is searched so often. Healthy body temperature actually varies a little from person to person and through the day, so treat 98.6 °F as a reference point.

At what temperature are Celsius and Fahrenheit equal?

At −40 degrees: −40 °C equals −40 °F. It's the only point where the two scales show the same number, because −40 × 1.8 + 32 = −40. That makes it a handy sanity check for any conversion formula or thermometer, and it's the first value in the Quick Reference table.

What are the freezing and boiling points of water in Fahrenheit?

Water freezes at 0 °C, which is 32 °F, and boils at 100 °C, which is 212 °F, at standard sea-level pressure. The 100-degree Celsius gap equals 180 Fahrenheit degrees, which is where the 9/5 (1.8) factor in the formula comes from, and the 32 accounts for the different freezing points.

What is a quick way to estimate °C to °F in your head?

Double the Celsius number and add 30. For 20 °C that gives about 70 °F, close to the exact 68 °F. The shortcut works best for everyday weather temperatures and drifts further off at the extremes — at 100 °C it gives 230 °F instead of 212 °F — so use the converter when accuracy matters.

Why does the formula add 32?

Because the scales start at different points. Water freezes at 0 on the Celsius scale but at 32 on the Fahrenheit scale, so after scaling the degree size by 9/5 you shift by 32 to line up the zero points. That's also why you can't convert a temperature change the same way: a rise of 10 °C is a rise of 18 °F, with no 32 added.

Key terms

Celsius (°C): The metric temperature scale; water freezes at 0° and boils at 100°.
Fahrenheit (°F): The US temperature scale; water freezes at 32° and boils at 212°.
Conversion Formula: °F = °C × 9/5 + 32.

Methodology, sources & limitations

This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.

For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.

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