Easily convert Celsius and Fahrenheit in your head

If you ever need to practically convert temperature from weather reports, this is a neat little trick. Just memorize a few values and you can easily convert. I saw this trick in a Lifehacker article. #shorts

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[davidmurphy]

Nice. Or, you can just ignore F as an antiquated load of nonsense.

[ScialCrisis]

Or the US could join the rest of the logical world and use Celsius. Even Kelvin would make more sense that F.

[snillor]

If I need a rough approximation - I just double celsius and add 30

[WillRennar]

3 points I have memorized to keep the formulas straight in my head:
-Boiling water (100C = 212F)
-Freezing water (0C = 32F)
-40 degrees below zero (-40C = -40F)

[davidlanger]

A student asked me at what temperature does mercury freeze? I replied: “40 degrees below zero.” Their follow up question was: “Is that on the Fahrenheit or Celsius scale?” I answered: “Yes”

[mybetterhalf]

A DJ in San Francisco taught me this decades ago~
"Thirty's hot,
Twenty's nice,
Ten's cold~
And zero's ICE!!"
Dr. Don Rose, KFRC radio....😎

[camembertdalembert]

as a french science teacher I more often need to convert Kelvin into °C (and vice versa). I don't care about °F.

[BigyetiTechnologies]

Or alternatively, and easier and quicker, double it, take away 10%, then add 32.

16 C - double it,
32 - take away 10%
28.8 - add 32
60.8 F

Or ditch Farenheit because it's bizarre, illogical and antiquated.

[itsgonnabeanaurfromme]

I miss the part where it's "easy to convert in your head"

[eminkilicaslan]

Ok, now I need to learn how to convert acceleration to burger per freedom^2

[Salien]

For weather, you can get an okay approximation with F=2C+30 or C=0.5*(F-30).

[zeinbotak]

Average Celsius vs Fahrenheit users: 🤬🤬
Average Kelvin and Rankine enjoyers: 😎😎

[kylew]

I basically remember what each common 10C interval is in F (0=32, 10=50, 20=68, 30=86) and then use a 2:1 ratio to step out from those points. It works pretty well because 9:5 is almost 2:1.

[silversurfer]

Americans should just learn Celsius from the beginning!

[Hokiebird]

A more general trick if you can’t remember the exact conversion formula: celsius works on a 100 degree scale between freezing and boiling. This can be thought of as a percent. Farhenheit has 180 degrees between freezing and boiling, but starts at 32 instead of 0. This logic written algebraically will give you the conversion formula, but is slightly more intuitive.

Example: What is 50C in Fahrenheit? Well, what is 50% of 180? 90. Now add 32 to get the answer of 122. Obviously this trick is less useful for percents that are more difficult to calculate in your head, but you could always round the number and make an estimate.

[MarielleSweden]

(F-30)/2 to get an idea of what C is. Super fast.

[pppluronwrj]

just ask your nerd friend, just say thanks afterwards. win win

[fpvflyer]

F->C You subtract 30 and divide by 2
C->F You multiply by 2 and add 30

(....both are very good estimates)

[YamamotoTV]

Correction: 4°C is only 39.2°F, not 40°F.

[toaster]

Ummm wat. Just double Celsius and add 30. Or subtract 30 from Fahrenheit and divide by 2.