Fahrenheit to Celsius Converter – °F to °C and °C to °F

Q: How do you convert F to C quickly?

Take away 32, then divide by 1.8. 68 °F is (68 − 32) ÷ 1.8 = 20 °C.

Q: What is the formula between F and C?

°C = (°F − 32) ÷ 1.8, and the other way, °F = °C × 1.8 + 32. 1.8 is the same as 9/5.

Q: How warm is 20 Celsius in Fahrenheit?

20 °C is 68 °F: 20 × 1.8 = 36, and 36 + 32 = 68.

Q: Is 100 Fahrenheit equal to 40 Celsius?

No. 100 °F is 37.78 °C, and 40 °C is 104 °F.

How to convert Fahrenheit to Celsius

Take away 32, then divide by 1.8. To go from Celsius to Fahrenheit, do the opposite: multiply by 1.8, then add 32. For kelvin, add 273.15 to the Celsius temperature.

°C = (°F − 32) ÷ 1.8

Here it is with your numbers:

Take away 32: 100 − 32 = 68.
Divide by 1.8: 68 ÷ 1.8 = 37.7778.
For kelvin, add 273.15 to the °C: 37.7778 + 273.15 = 310.9278.
Round to two decimals: 37.78 °C.

It means 100 °F on one thermometer reads 37.78 °C on the other.

Source NIST Guide to the SI (SP 811) · Appendix B.9, conversion factors: temperature ↗

Fahrenheit to Celsius chart

Fahrenheit	Celsius	Kelvin
−40 °F	−40.00 °C	233.15 K
0 °F	−17.78 °C	255.37 K
32 °F	0.00 °C	273.15 K
50 °F	10.00 °C	283.15 K
60 °F	15.56 °C	288.71 K
68 °F	20.00 °C	293.15 K
70 °F	21.11 °C	294.26 K
75 °F	23.89 °C	297.04 K
80 °F	26.67 °C	299.82 K
90 °F	32.22 °C	305.37 K
100 °F	37.78 °C	310.93 K
212 °F	100.00 °C	373.15 K
325 °F	162.78 °C	435.93 K
350 °F	176.67 °C	449.82 K
375 °F	190.56 °C	463.71 K
400 °F	204.44 °C	477.59 K
425 °F	218.33 °C	491.48 K
450 °F	232.22 °C	505.37 K

Celsius to Fahrenheit chart

Celsius	Fahrenheit	Kelvin
−40 °C	−40.00 °F	233.15 K
−20 °C	−4.00 °F	253.15 K
−10 °C	14.00 °F	263.15 K
0 °C	32.00 °F	273.15 K
10 °C	50.00 °F	283.15 K
15 °C	59.00 °F	288.15 K
20 °C	68.00 °F	293.15 K
25 °C	77.00 °F	298.15 K
30 °C	86.00 °F	303.15 K
37 °C	98.60 °F	310.15 K
40 °C	104.00 °F	313.15 K
100 °C	212.00 °F	373.15 K
160 °C	320.00 °F	433.15 K
180 °C	356.00 °F	453.15 K
200 °C	392.00 °F	473.15 K
220 °C	428.00 °F	493.15 K

Converted values are rounded to two decimals. −40 is where the two scales meet: −40 °F is −40 °C.

What is kelvin?

Kelvin (K) is the temperature unit of the International System of Units (SI). It starts at absolute zero, 0 K, which is −273.15 °C or −459.67 °F, so it has no negative numbers. A change of 1 K is the same size as a change of 1 °C, and kelvin is written without a degree sign.