Fahrenheit vs Celsius for day to day use ...and Regulo

You’re right – everyone should use the Regulo system, at least for oven temperatures. :wink:

For day to day use Regulo suffers from the same problems as Celsius. Humans can detect temp changes as small as 1 degree F, this means that F is useful without using decimals. Also the range, 0 degrees F is very cold and 100 F is very hot for humans. Celsius requires negative numbers for year round daily use.

The 0 - 100 is of little use as there is no kiloCelsius etc.


It’s particularly not-horrible for oven temperatures, especially if you want to make your recipes obscure outside The Commonwealth.

But for other day to day uses it’s no good at all since it’s only defined between 107 and 270C (225 and 520F).

Under no plausible scenario will Regulo displace other scales already in use. But as a technical matter the range problem could be solved by using negative numbers, which would be inconvenient for day to day use. Celsius suffers from the same problems but to a lesser degree.

For more about Celsius (Centigrads):

Or about Anders Celsius, the person:

That was a necessary element of my little joke.

Not without doing violence. As laid out you’d have to use 1/8, 1/16, 1/32, 1/64 just to get down to 100F

Yes, but also a necessary element of my explanation of how it could be adapted for day to day use. But looks like not linear? The last two 1/4 and 1/2 breaks the 25 degree increments?

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Your point? I expect everyone on here knows what Celsius is, and most of us know what Centigrade was as well.

Some of us even know that “normal” body temperature is listed at 98.6F because it was originally determined on a population of 250 people – in Centigrade – as 37C +/- 1C.

It’s broken at the top end as well – high number is +45F from the next.

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It would be very weird if that was not the case.

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“Oh, you mean European degrees…”

Maybe “everybody knows what Celsius is, and most also know what Centigrade is as well” (although I’m not sure if that is so)

Fahrenheit, on the other hand, is a mystery to most people outside the US and the few countries and territories that still use it. (Which is most of the world’s population)
It doesn’t harm to put in a link to the Wikipedia page for Fahrenheit for the many members here that belongs to that last group:

Kelvin degrees are mainly used by scientists etc. and not by the general public, but it doesn’t harm to add that to the knowledge bank:


And Rankine gets no love? <weep>

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No, since that is even more obscure than Kelvin.
But maybe you want to add in a link?

We use Celsius on the ship of course. So as a result I am familiar enough but at sea I mostly only encounter temps above 0C. Same in the engine room. All temps in C so the engineers are intuitively familiar but not so for cold temps.

I was once asked what was typical for Maine winters. I said about 20F was a typically winter day. The person I was talking to was from California but had spent one winter in Russia so wanted to know in C which I didn’t know off the top of my head.

When I got home I switched the family over to C for a winter. Worked out OK for us after a bit but confusing for interaction with others. I took my daughter to X-C ski practice one very cold day (-20C) and when I got out of the car lightly dressed, a vest, no coat, , the coach said I was dressed more for 20 degrees. I told him it was 20 degrees in the car. He just gave me a puzzled look. The car was 20C. Toasty warm. My daughter had to explain to me later what had happened.

Switched back to F after that.

Kelvin’s not obscure! Every high school kid taking science courses knows about it. Rankine is just Kelvin but in Fahrenheit units, but it’s a lot more obscure because science everywhere uses C and K.


0F is ~-18C, and -40F is -40C. That should be enough to get a feel for cold.

10C is 50F
20C is ~70F (68F)
30C is ~85F (86F)
(37C is 98.6F)
40C is ~100F (104F)
50C is ~120F (122F)
60C is 140F
70C is ~160F (158F)
80C is ~175F (174F)
90C is ~195F (194F)

I meant being able to look at the thermometer and know what the weather is like without having to convert in your head. It comes easy for 0-30 C because that’s what we use on the ship.

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