# Fº & Cº **URL:** \ **Category:** Factual Questions\ **Created:** [September 20, 1999, 7:10pm UTC](https://boards.straightdope.com/t/f-c/3449 "1999-09-20T19:10:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Lucky](https://avatars.discourse-cdn.com/v4/letter/l/e9c0ed/32.png) [@Lucky](https://boards.straightdope.com/u/Lucky)\ **Post date:** [September 20, 1999, 7:10pm UTC](https://boards.straightdope.com/t/f-c/3449/1 "1999-09-20T19:10:00Z")
My electronic converting gadget broke and I can’t remember the formula for converting Farenheit to Celsius. Anybody? ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 20, 1999, 7:37pm UTC](https://boards.straightdope.com/t/f-c/3449/2 "1999-09-20T19:37:00Z")
(C x 9/5) + 32 = F (F - 32) x 5/9 = C * * * Tom~ ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 20, 1999, 7:50pm UTC](https://boards.straightdope.com/t/f-c/3449/3 "1999-09-20T19:50:00Z")
You can also try this site for various conversions: [http://microimg.com/science/](http://microimg.com/science/) * * * Tom~ ---
**Author:** ![Lucky](https://avatars.discourse-cdn.com/v4/letter/l/e9c0ed/32.png) [@Lucky](https://boards.straightdope.com/u/Lucky)\ **Post date:** [September 20, 1999, 7:58pm UTC](https://boards.straightdope.com/t/f-c/3449/4 "1999-09-20T19:58:00Z")
Tomndebb: Thanks 🙂 * * * “I think it would be a great idea” Mohandas Ghandi’s answer when asked what he thought of Western civilization ---
**Author:** ![Strainger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/strainger/32/244_2.png) [@Strainger](https://boards.straightdope.com/u/Strainger)\ **Post date:** [September 20, 1999, 8:04pm UTC](https://boards.straightdope.com/t/f-c/3449/5 "1999-09-20T20:04:00Z")
Lucky, you can also download a free conversion tool here: [www.joshmadison.com/software](http://www.joshmadison.com/software) ---
**Author:** ![DGS](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@DGS](https://boards.straightdope.com/u/DGS)\ **Post date:** [September 20, 1999, 10:18pm UTC](https://boards.straightdope.com/t/f-c/3449/6 "1999-09-20T22:18:00Z")
Also check out the “Constants and equations page” at [http://www.tcaep.co.uk/](http://www.tcaep.co.uk/) ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [September 21, 1999, 12:29am UTC](https://boards.straightdope.com/t/f-c/3449/7 "1999-09-21T00:29:00Z")
I recently learned a new one that’s much simpler to remember: To convert from F to C, take the temperature, add forty, multiply by 5/9, and subtract forty. e.g., 32 F +40 = 72 x 5/9 = 40 - 40 = 0 75 F + 40 = 115 x 5/9 = 63.888 - 40 = 23.888 To convert the other way, add forty, multiply by 9/5 and subtract 40 again. e.g. 45 C +40 = 85 x 9/5 = 153 -40 = 113 It works nicely and is easier to remember. Just remember Celsius degrees are larger than Fahrenheit. * * * [www.sff.net/people/rothman](http://www.sff.net/people/rothman) ---
**Author:** ![Undead\_Dude](https://avatars.discourse-cdn.com/v4/letter/u/e19adc/32.png) [@Undead\_Dude](https://boards.straightdope.com/u/Undead_Dude)\ **Post date:** [September 21, 1999, 12:44am UTC](https://boards.straightdope.com/t/f-c/3449/8 "1999-09-21T00:44:00Z")
I just had to say that this +40/-40 method is very clever! I’ll use that for now on. 🙂 ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [September 21, 1999, 1:09am UTC](https://boards.straightdope.com/t/f-c/3449/9 "1999-09-21T01:09:00Z")
If you don’t need to be too precise and are dealing with “normal” temperatures, you can get by with a really quick cheat. To convert C to F - Double and add 30 To convert F to C - Subtract 30 and half. For example, if the temperature is 25C then the above gives 80F (actual is 77F) If the temperature is 85F this gives 27.5C (actual is just over 29C) * * * “You can’t run away forever; but there’s nothing wrong with getting a good head start.” — Jim Steinman Dennis Matheson — [Dennis@mountaindiver.com](mailto:Dennis@mountaindiver.com) Hike, Dive, Ski, Climb — [www.mountaindiver.com](http://www.mountaindiver.com) ---
**Author:** ![TheIncredibleHolg](https://avatars.discourse-cdn.com/v4/letter/t/8797f3/32.png) [@TheIncredibleHolg](https://boards.straightdope.com/u/TheIncredibleHolg)\ **Post date:** [September 21, 1999, 7:52am UTC](https://boards.straightdope.com/t/f-c/3449/10 "1999-09-21T07:52:00Z")
Now, if someone could tell me why it should be easier to perform two additions/subtractions instead of one – just because the number ends in 0? And you still have to remember if you must add first and then subtract or vice versa, and whether to multiply by 5/9 or 9/5… Personally, I think division by 9 is the hard part (relatively speaking), and there’s just no getting around that without loss of accuracy. ---
**Author:** ![E1skeptic](https://avatars.discourse-cdn.com/v4/letter/e/3da27b/32.png) [@E1skeptic](https://boards.straightdope.com/u/E1skeptic)\ **Post date:** [September 21, 1999, 8:15am UTC](https://boards.straightdope.com/t/f-c/3449/11 "1999-09-21T08:15:00Z")
Stupid little “rules of thumb” that for some reason remain locked in your brain forever: Starting from 04°C, and adding 12 each time, the temperature in °F is the number (in °C) reversed. Like this: 04°C = 40°F 16°C = 61°F 28°C = 82°F 40°C = 104°F (just add the “1” before te “0”) 52°C = 125°F, and so forth. It’s pretty accurate, and if you memorise certain figures, and don’t need mathematical accuracy, all you have to do is add 2°F per °C. Go figure. ---
**Author:** ![NanoByte](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@NanoByte](https://boards.straightdope.com/u/NanoByte)\ **Post date:** [September 21, 1999, 9:42am UTC](https://boards.straightdope.com/t/f-c/3449/12 "1999-09-21T09:42:00Z")
Come on! All these people with gimmicks cluttering up their minds. If you use the straightforward formulae given above AND THINK WHAT YOU’RE DOING, there’s no problem. You have a ratio of 5 wrt 9. You have an offset of +32 F at freezing and C starts there with 0. You know C has bigger degrees than F, because its range of numbers is smaller than those of the corresponding F degrees. Ever since (and, yeah, plenty of people before) calculators, people has chosen not to think what they’re doing. Ray (Now, what _ **was** _ I doing?) ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [September 21, 1999, 9:56am UTC](https://boards.straightdope.com/t/f-c/3449/13 "1999-09-21T09:56:00Z")
Actually converting the scales is no mystery to me. What _is_ a mystery is, How do you make those cool little degree zeros you used in the topic of this post? Skeptic used them in his post as well. Lets have the dope on em. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 21, 1999, 2:18pm UTC](https://boards.straightdope.com/t/f-c/3449/14 "1999-09-21T14:18:00Z")
ASCII ALT + codes. There were a couple of threads on them in the “Comments” Forum some time back, you might be able to find a list. If you have Windows, run Explore for the file charmap.exe, then drag in onto your desktop as a shortcut. Each character is displayed on a grid. Select the appropriate font. Clicking on a character displays the ASCII ALT+ code on the lower right. To get °, hold down the ALT key and type 0176 on the numeric pad. The rest work the same way. There are also some shortcuts that donot use 4 digits, but while I have a list of them, I have never seen them explained. If you have a Mac, I can’t help. * * * Tom~ ---
**Author:** ![EvilGhandi](https://avatars.discourse-cdn.com/v4/letter/e/f17d59/32.png) [@EvilGhandi](https://boards.straightdope.com/u/EvilGhandi)\ **Post date:** [September 21, 1999, 2:34pm UTC](https://boards.straightdope.com/t/f-c/3449/15 "1999-09-21T14:34:00Z")
alt 0176 ° yep that does it, Thanks TomnDeb. ---
**Author:** ![E1skeptic](https://avatars.discourse-cdn.com/v4/letter/e/3da27b/32.png) [@E1skeptic](https://boards.straightdope.com/u/E1skeptic)\ **Post date:** [September 22, 1999, 1:00pm UTC](https://boards.straightdope.com/t/f-c/3449/16 "1999-09-22T13:00:00Z")
He, he, he, he… my keyboard has it as default (spanish keyboard). All I have to do is strike “alt” plus the ° key! 🙂 ---
**Author:** ![NeedAHobby](https://avatars.discourse-cdn.com/v4/letter/n/3d9bf3/32.png) [@NeedAHobby](https://boards.straightdope.com/u/NeedAHobby)\ **Post date:** [September 23, 1999, 5:11am UTC](https://boards.straightdope.com/t/f-c/3449/17 "1999-09-23T05:11:00Z")
You could always use the HTML entity code “°” to make the °. That way, it’s cross-platform and standardized. By the way, on a Mac, I think the degree is either Option-6 (like the ^) or Option-Shift-8 (like the \*, and like the Option-8 bullet character). * * * Hey, aren’t you supposed to be at work? ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [September 22, 1999, 8:49pm UTC](https://boards.straightdope.com/t/f-c/3449/18 "1999-09-22T20:49:00Z")
RealityChuck wrote: > [@](#): > > To convert from F to C, take the temperature, add forty, multiply by 5/9, and subtract forty. The reason this works is that -40° Fahrenheit is the same temperature as -40° Celsius. Personally, I prefer to work in Kelvins. * * * Visit the Internet Stellar Database at [www.stellar-database.com](http://www.stellar-database.com) ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [September 24, 1999, 6:52am UTC](https://boards.straightdope.com/t/f-c/3449/19 "1999-09-24T06:52:00Z")
You can also superscript a lower case ‘o’ with the (sup) (/sup) HTML codes (of course, substitute the parenthesis with angle brackets – also, subscript can be done with ‘sub’ in the code). So, \\code:\\\H[sub]2[/sub]O boils at 100[sup]o[/sup] C. ```auto becomes **H[sub]2[/sub]O boils at 100[sup]o[/sup] C.** Peace. ``` ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [September 25, 1999, 5:29am UTC](https://boards.straightdope.com/t/f-c/3449/20 "1999-09-25T05:29:00Z")
Darn it!  I thought the \*\*\code \\*\*code was supposed to preserve formatting codes.  \ I guess I’ll force the issue with \Netscape Composer\.  The code looks like this: \\ \ \**\\H\2\O boils at 100\o\ C.\\**\ \ \\ There, that’ll show **\\UBB\\** who’s boss! € \P\\e\\a\\c\\e\