How do I convert Fahrenheit to Celsius?

Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. Written out: °C = (°F − 32) × 5/9. For example, 98.6°F − 32 = 66.6, and 66.6 × 5/9 = 37°C.

What is 0°C in Fahrenheit?

0°C equals 32°F. That is the freezing point of water at standard atmospheric pressure, and it is why the Fahrenheit scale puts freezing at 32 rather than 0.

What is 100°C in Fahrenheit?

100°C equals 212°F — the boiling point of water at sea level. The 100-degree gap between freezing and boiling in Celsius becomes a 180-degree gap in Fahrenheit.

What is normal body temperature in Fahrenheit?

Normal human body temperature is about 37°C, which is 98.6°F. A reading of 38°C (100.4°F) or higher is generally considered a fever.

Is there a quick way to estimate the conversion in my head?

Yes. To go from Celsius to Fahrenheit, double the number and add 30. So 20°C is roughly 20 × 2 + 30 = 70°F (the exact answer is 68°F). It is close enough for weather and only drifts a few degrees apart from the true value.

At what temperature are Celsius and Fahrenheit equal?

At −40 degrees. −40°C and −40°F are exactly the same temperature — the single point where the two scales cross. It is the only temperature where the number is identical on both.

What is 180°C in Fahrenheit for an oven?

180°C equals 356°F, usually rounded to 350°F (gas mark 4) in recipes. Most ovens are not precise enough for the few-degree difference to matter, so 350°F is the standard equivalent.

Conversion

Celsius to Fahrenheit

Convert any temperature between Celsius and Fahrenheit — both directions, live as you type. Formula, step-by-step working, a full lookup chart, and oven temperatures included.

Convert a temperature

°C → °F

Temperature in Celsius (°C)

°C

100 °C equals

212°F

Hot

How it works out

1
Start with the formula
°F = (°C × 9/5) + 32
2
Substitute your value
°F = (100 × 9/5) + 32
3
Multiply by 9/5
°F = 180 + 32
4
Add 32
°F = 212

Celsius

100°

Fahrenheit

212°

Kelvin

373.15

Updates as you type.

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The basics

Celsius and Fahrenheit, side by side

Celsius and Fahrenheit are two scales for the same thing — how hot or cold something is. They disagree on two things: where they put zero, and how big a degree is. Pin those two differences down and every conversion becomes one short formula.

°F = (°C × 9/5) + 32

Celsius → Fahrenheit

Scale the degree size by 9/5, then shift the zero point up by 32. Celsius anchors zero at water's freezing point; Fahrenheit puts that same point at 32.

20°C → 20 × 1.8 + 32 = 68°F

°C = (°F − 32) × 5/9

Fahrenheit → Celsius

Undo the conversion in reverse order: remove the 32-degree offset first, then shrink the degree size back down by 5/9. Same relationship, run the other way.

98.6°F → (98.6 − 32) × 5/9 = 37°C

Method

How to convert by hand

Three steps going from Celsius to Fahrenheit. The same steps in reverse get you back.

1
Multiply by 9/5
Take your Celsius value and multiply it by 9/5, which is the same as multiplying by 1.8. This rescales a Celsius-sized degree into a Fahrenheit-sized one.
37 × 9/5 = 66.6
2
Add 32
Add 32 to shift the zero point. Celsius starts at water's freezing point, but Fahrenheit marks that at 32, so every reading needs the offset.
66.6 + 32 = 98.6
3
Read the result
The number you land on is the temperature in Fahrenheit. To reverse, subtract 32 first, then multiply by 5/9.
37°C = 98.6°F

Worked examples

See it both ways

The same procedure, run forward, backward, and as a head-math shortcut. Switch tabs to compare.

Convert 37°C to Fahrenheit

Formula: °F = (°C × 9/5) + 32

Substitute: °F = (37 × 9/5) + 32

Multiply: °F = 66.6 + 32

37°C = 98.6°F

Quick chart

The full conversion chart

Looking up a specific value — “what is 37°C in Fahrenheit?” or “how hot is 350°F?” Switch direction and pick a range to read it straight off.

−10°C

14°F

−5°C

23°F

0°C

32°F

5°C

41°F

10°C

50°F

15°C

59°F

20°C

68°F

25°C

77°F

30°C

86°F

35°C

95°F

40°C

104°F

Each row: °C on top, °F below. Dot shades how the temperature feels.

Reference

Temperatures worth knowing

Anchor points that make every other temperature easier to place. All converted from their Celsius definitions.

Landmark

Celsius

Fahrenheit

Absolute zeroColdest possible

−273.15°C

−459.67°F

Freezer (food)

−18°C

−0.4°F

Crossover point°C = °F

−40°C

−40°F

Water freezesIce point

0°C

32°F

Refrigerator

4°C

39.2°F

Cool day

10°C

50°F

Room temperature

21°C

69.8°F

Warm day

30°C

86°F

Body temperatureNormal

37°C

98.6°F

Fever threshold

38°C

100.4°F

Hot bath

40°C

104°F

Water boilsAt sea level

100°C

212°F

In the kitchen

Oven temperature conversions

Recipes drift between °C, °F, and gas marks. Here is the standard cross-reference, with the round Fahrenheit figure cooks actually dial in.

Celsius

Fahrenheit

Gas mark

Description

110°C

230°F

Very cool

120°C

248°F

Very cool

140°C

284°F

Cool

150°C

302°F

Cool

160°C

320°F

Warm

180°C

356°F

Moderate

190°C

374°F

Mod. hot

200°C

392°F

Fairly hot

220°C

428°F

Hot

230°C

446°F

Very hot

240°C

464°F

Very hot

Fahrenheit values are exact; recipes round to the nearest 25 (e.g. 180°C → 350°F).

Worth knowing

Facts that make it click

A handful of quirks about the two scales that turn rote conversion into intuition.

−40°C = −40°F

The crossover point

There is exactly one temperature where both scales read the same number. Below it Celsius is the larger figure; above it Fahrenheit is.

1°C = 1.8°F

Degrees are different sizes

A one-degree change in Celsius is a 1.8-degree change in Fahrenheit. That is why Fahrenheit numbers move faster as the weather shifts.

0–100°C → 32–212°F

Water sets the anchors

Celsius pins zero and one hundred to water freezing and boiling. The same span is 32 to 212 in Fahrenheit — a 180-degree gap.

double + 30

The pocket shortcut

For everyday weather, doubling the Celsius value and adding 30 lands within a few degrees of the exact Fahrenheit answer — fine for deciding on a jacket.

K = °C + 273.15

Kelvin is just shifted Celsius

Science uses Kelvin, which shares the Celsius degree size and only moves the zero down to absolute zero — the coldest anything can get.

98.6°F = 37°C

Body temperature, both ways

The classic 98.6°F comes straight from rounding 37°C. A reading at or above 38°C (100.4°F) is the usual fever line.

Origins

Where the two scales came from

Two eighteenth-century instrument makers, two different choices about where to put zero.

Fahrenheit (1724)

Daniel Gabriel Fahrenheit, a German physicist, built precise mercury thermometers and set his zero at the coldest temperature he could reliably reproduce with a brine mixture. Body temperature and water's freezing point fell where they fell. The result is the scale still used day to day in the United States.

Celsius (1742)

Anders Celsius, a Swedish astronomer, tied his scale to water — freezing and boiling — and split the gap into a clean hundred degrees. Almost the entire world adopted it, and science standardized on its Kelvin cousin. Its tidy zero-to-hundred span is why most of the planet measures weather in Celsius.

Common mistakes

Where conversions go wrong

Almost every error is one of these three. Spot them and your answers stay right.

add 32 last

Order of operations

Going C to F, multiply by 9/5 before adding 32 — not after. Adding first inflates the answer by about 25 degrees.

9/5 vs 5/9

Flipping the fraction

C to F uses 9/5 (bigger); F to C uses 5/9 (smaller). Swapping them sends the result the wrong way entirely.

−32 first

Forgetting to subtract

Going F to C, subtract 32 before multiplying by 5/9. Skip it and you scale the offset by mistake.

FAQ

Common questions

Multiply the Celsius temperature by 9/5 (which is 1.8) and add 32. Written out: °F = (°C × 9/5) + 32. For example, 20°C × 1.8 = 36, and 36 + 32 = 68°F.

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