Temperature Conversion Celsius to Fahrenheit

Temperature Converter: F to C or C to F

By The Old Farmer's Almanac

Looking to change Fahrenheit to Celsius or Celsius to Fahrenheit? Use our Celsius to Fahrenheit temperature converter, or see our temperature conversion chart to go from C to F or F to C.

About Fahrenheit and Celsius

The Fahrenheit temperature scale is named for German physicist Daniel Gabriel Fahrenheit and is used primarily in the United States.

The Celsius temperature scale—originally centigrade and later renamed for Swedish astronomer Anders Celsius—is used almost everywhere else in the world.

F to C: Fahrenheit to Celsius Conversion Calculator


Enter a value for Fahrenheit or Celsius to convert to the other.

F to C: Fahrenheit to Celsius Conversion Formula

To convert temperatures in degrees Fahrenheit to Celsius, subtract 32 and multiply by .5556 (or 5/9).

  • Example: (50°F - 32) x .5556 = 10°C

Fahrenheit to Celsius Conversion Chart



-40°F -40°C
-30°F -34°C
-20°F -29°C
-10°F -23°C
0°F -18°C
10°F -12°C
20°F -7°C
32°F 0°C
40°F 4°C
50°F 10°C
60°F 16°C
70°F 21°C
80°F 27°C
90°F 32°C
100°F 38°C

C to F: Celsius to Fahrenheit Conversion Formula

To convert temperatures in degrees Celsius to Fahrenheit, multiply by 1.8 (or 9/5) and add 32.

  • Example: 30°C x 1.8 + 32 = 86°F

Celsius to Fahrenheit Conversion Chart



-40°C -40°F
-30°C -22°F
-20°C -4°F
-10°C 14°F
0°C 32°F
10°C 50°F
20°C 68°F
30°C 86°F
40°C 104°F
50°C 122°F
60°C 140°F
70°C 158°F
80°C 176°F
90°C 194°F
100°C 212°F

Other Conversions

  • Another interesting temperature conversion is turning cricket chirps into degrees F. Did you know that crickets can tell you how cold it is? Find out how to tell the temperature from cricket chirps here!
  • Looking for some cooking conversions? This page has everything you need to know about easy substitutions and conversions in the kitchen.
  • If you’re a little confused about Celsius, chances are that the metric system might be tough for you too. Check out another handy conversion chart for the metric system.


This article was originally published in 2008 and is regularly updated.

Reader Comments

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Y=a+bx (regression equation)
Y= Fahrenheit
x= Celsius

Awesome website

This was really helpful for school work!

Mathematical literacy

Individual Activity 5:
Complexity=4, Mode=f to c
Do the following conversions. Round to nearest tenth where necessary.
1. 55 oF = oC
2. 67 oF = oC

EASIEST way to convert Celsius to Fahrenheit

The Quickest way I've found converting ℃ to ℉ without doing fractions or decimals is to round off to the nearest 10th (i.e.10℃,20℃,30℃.....) just remember 0℃ is 32℉ and there is 18℉ difference between every 10℃ and 9℉ between every 5℃. If you need a more accurate reading just add or subtract 1.8. Examples:
10℃=50℉ 15℃=59℉ 11℃=51.8℉ 12℃=53.6℉.....
20℃=68℉ 25℃=77℉ 21℃=69.8℉ 22℃=71.6℉.....
30℃=86℉ 35℃=95℉ 31℃=87.8℉ .......
40℃=104℉ 45℃=113℉ .....
50℃=122℉ 55℃=131℉......
60℃=140℉ 65℃=149℉.....
70℃=158℉ 75℃=167℉.....
80℃=176℉ 85℃=185℉.....
90℃=194℉ 95℃=203℉....
100℃=212℉ 105℃=221℉

temperature conversion

Here's a much simpler method for those not keen on algebraic equations. For a good approximate:
To convert centigrade to Fahrenheit: simply double the degrees in C, and add 30 .
for example 20deg C is app equal to 40 plus 30= 70 def F

To convert Fahrenheit to Centigrade: simply subtract (minus, or take away) 30 from degrees in F, and half it
for example: 70 deg F i.e 70-30 = 40, divide 40 by 2 ( or half that amount) = 20 deg C


how to solve
each measure of temperature


There are three popular temperature scales used in math and science. You will often find yourself having to convert units between these scales. Using examples, we will learn how to perform these conversions, and also relate temperatures expressed in Kelvins, degrees Celsius and degrees Fahrenheit.

Easy Way to Convert from Celsius to Fahrenheit:

Instead of using F=(9/5)C+32; it is easier if you don't have a calculator to use (2)C+32-C/5.

Estimates are easy if you round to the nearest 5.


20C = 2(20)+32-20/5=40+32-4=68F

The benefit of using this formula is that it is easier to use in your head and the answer is exact; So it works in a calculator too!


So what is the formla for izt then


it is not "izt" it is usually "it" but the truth is I don't know...

My reference notes from what I learned here

Convert Celsius To Fahrenheit
1. Multiply # By 1.8

2. 20x1.8=36

3. Add (32)

4. 36+32=68

Convert Fahrenheit To Celsius

1. Subtract (32) From #

2. 68-32=36

3. Multiply by .5556 (or 5/9)

4. 36x.5556=20

4.1. Or 56 Instead Of .5556
4.2. 36x56=2016
4.3. Remove 16

Using Method 5 Divided By 9
1. Multiply By 5
2. 36x5=180
3. Divide By 9
4. Turn 9 To 10
5. 180/10
6. Half 180 To 90 And 10 To 5
7. Half 90 To 40 And 5 To 2
8. Half 40 to 20 And 2 To 1
9. 20/1=20

7. 40 is easier to half then 45
Keep going until you can't half 10 anymore or don't half 2

My notes to help remember this. Used to be good at math suck at it now


This was very helpful! Thanks so much!

82•F - 32 = 50 (now) 50*.556

82•F - 32 = 50 (now)
50*.556 = 27.8•C (exact)

Unless you need the EXACT

Unless you need the EXACT number, you can do a quick conversion in your head:

70F - 32 = 38 divided by 2 = 19, then add 1 or 2(remember, this is close enough, not exact)= 21C. The exact conversion would be 21.1.

Another example is 40F - 32 = 8 divided by 2 = 4C. For a lower F temperature to start with, you don't have to add much. In this case, the exact conversion is 4.4.

why is it so many formula

why is it so many formula method to convert in the different version?

F into C Subtract 32,

F into C
Subtract 32, multiplyng by 5, and Divided by 9

50 F = C
90/9=10 C

gud to understand but update

gud to understand but update the information day to day

Gud to start spelling

Gud to start spelling correctly, too #itsspeltgood

Easiest way: Google it. Type

Easiest way: Google it. Type "convert x degrees Fahrenheit into Celsius" That goes for many measurements. For example, kg-pounds, m-inch and etc. It works both ways.


99.5 f is how mutch celsius



Yo ppl! Conversion of C to

Yo ppl!

Conversion of C to F.
Take the value of C, multiply it by 2.
then subtract the first digit of the answer from the answer, then simply add 32.
Example: 10C to F ?

Go vice versa too.
Have fun!

This will not work is above

This will not work is above 99C or below -99 C
C to F
C+40 *9/5-40=F
will work at any temp

Formula is not always correct

If you use this formula for simply 100C (Boiling which should equal in the end 212F) it works out 100Cx2=200, 200-2=198, 198+32=230F, so it works out incorrectly in this situation. the formula is not always correct so it should not be used as a solid formula. It also is incorrect in other examples that I worked. Wish it worked because it's simple but not.

This Formula is correct

This formula does work for 100C and above. Mathematically, the formula works, and is simpler when written out algebraically.
i.e. - 100Cx2 = 200, 200-(20) = 180, 180+32 = 212F.
For a completely accurate formula... C*2 = A, A-(A/10) = B, B + 32 = F
199Cx2 = 398, 398-(39.8)= 358.2 + 32 = 390.2F
6511Cx2 = 13022, 13022-(1302.2)= 11719.8, 11719.8+32= 11751.8

Copied from wikitravel.org: A

Copied from wikitravel.org:
A nice little poem to remember for Celsius...
Zero is freezing.
10 is not.
20 is warm.
and 30 is hot!

Regarding poem

If 20 is warm and 30 is hot, please spend sometime in India or Arab countries. :)

Hi Nasser:

Hi Nasser:
The local geographic elevation and the humidity of the air make the differences how the human body interprets the environment to the brain.

It's even easier.... If you

It's even easier....
If you notice, the Celcius and Fahrenheit scales are equal at -40 degrees.
The conversion formula (to go either way) would be
temp = (old temp + 40) X - 40

where X is 5/9 to convert to Celcius
and X is 9/5 to convert to Fahrenheit

One formula does the trick.
To Convert 0 degrees Celcius to Fahrenheit:
temp = (0 + 40) 9/5 + 40
temp = 40 * 9/5 + 40
temp = 72 - 40
temp = 32 degrees Fahrenheit

Thank you so much! My math

Thank you so much! My math book is so complicated. Instead of just simply saying what you said, It said

F + 9/5C + 32

9/5C + 32 + F

9/5C + 32 - 32 = F -32

9/5C = F - 32

5/9 x 9/5C = 5/9(F-32)

C = 5/9(F - 32)