# Who measures angles in "grads"?
**URL:** https://boards.straightdope.com/t/who-measures-angles-in-grads/290217
**Category:** Factual Questions
**Created:** [February 15, 2005, 5:05pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217 "2005-02-15T17:05:15Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)
#### Post date: [February 15, 2005, 5:05pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/1 "2005-02-15T17:05:15Z")
If you’ve ever used, or seen, a scientific calculator, you’ve seen a key to switch angle units between degrees, radians, and grads. Degrees and radians are both pretty common, of course, but why does anyone want to divide a right angle into 100 grads instead of 90 degrees? Who uses that feature, and why?
---
### Author:  [@MikeS](https://boards.straightdope.com/u/MikeS)
#### Post date: [February 15, 2005, 5:21pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/2 "2005-02-15T17:21:36Z")
The [Wikipedia article](http://en.wikipedia.org/wiki/Gradian) on the gon and the gradian has a few details (although it’s admittedly sparse.)
---
### Author:  [@\_xiao\_wenti](https://boards.straightdope.com/u/_xiao_wenti)
#### Post date: [February 15, 2005, 5:36pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/3 "2005-02-15T17:36:22Z")
We have a deposition tool that measures the substrate carousel position in grads. Really annoying. The company is out of business. I don’t know if the two are linked.
---
### Author:  [@chappachula](https://boards.straightdope.com/u/chappachula)
#### Post date: [February 15, 2005, 5:49pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/4 "2005-02-15T17:49:58Z")
[QUOTE=ElvisL1ves]
why does anyone want to divide a right angle into 100 grads instead of 90 degrees?[/QUOTE]
grads are a decimal unit, and are subdivided into simple 100ths, just like the meter is subdivided into cetimeters…Degrees are not decimal units–they are subdivided into 60 minutes and then another 60 seconds.So every time you want to do a simple calculation (say, adding two angles), you have to do first do TWO extra steps–convert the seconds into decimal minutes, then convert the decimalized minutes into decimal degrees. (most pocket calculators have a simple button that does this, but it still requires you to press an extra button before doing the actual calculation that you want to complete.
try this example–add two angles : 75 degrees, 45 minutes, 20 seconds plus 25 degrees 15 minutes 10 seconds.
or add 75.753 plus 25.251
Which is easier?
Land surveyors (those guys you see on the side of the road with an instrument mounted on a tripod) make hundreds or even thousands of angle measurements during a day’s work.
Grads are great!!!
---
### Author:  [@Martin\_Hyde](https://boards.straightdope.com/u/Martin_Hyde)
#### Post date: [February 15, 2005, 6:16pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/5 "2005-02-15T18:16:30Z")
The only real use or experience I have with angles is mathematically, and in mathematics I always prefer (especially when using calculus or any higher math) radians.
---
### Author:  [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)
#### Post date: [February 15, 2005, 6:44pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/6 "2005-02-15T18:44:43Z")
With the advent of wide-spread automated calculation, grads become yet another metric solution in search of a problem.
I was trying to make a joke based on “grads” vs. “undergrads”, but it was getting too contrived to bother with…
---
### Author:  [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)
#### Post date: [February 15, 2005, 7:24pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/7 "2005-02-15T19:24:37Z")
Does anyone still measure angles in minutes and seconds, or have they gone the way of the slide rule?
---
### Author:  [@flight](https://boards.straightdope.com/u/flight)
#### Post date: [February 15, 2005, 7:34pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/8 "2005-02-15T19:34:32Z")
The only time I see minutes and seconds still used is for latitude and longitude.
---
### Author:  [@iwakura43](https://boards.straightdope.com/u/iwakura43)
#### Post date: [February 15, 2005, 7:36pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/9 "2005-02-15T19:36:03Z")
I don’t know if they use minutes and seconds in the day-to-day work, but I’ve certainly heard my father, a tunnel engineer, refer to angles in those terms.
---
### Author:  [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)
#### Post date: [February 15, 2005, 8:12pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/10 "2005-02-15T20:12:15Z")
When I first heard about grads (they were a third angular measure converrsion available on the HP series of calculators) I asked the same question. At the time, I was told that grads were used in the military.
I never understood the need for grads, since they are so close to degrees (90 degrees = 100 grads), and the explanations given to me for them never made sense. (You don’t get much more resolution with grads, the number of degrees is as easy to hear under battlefield conditions as the number of grads, and you can use degrees with decimal fractions instead of degree-minute-seconds if you want ease od calculation). On the other hand, it’s easy to take halves and thirds of 90 degrees, and the values of sines and cosines for 30 degrees and 60 degrees are significant and easy to remember. all grad measure can give you is something significant at 50 grads = 45 degrees.
Nope. Can’t see the advantage.
---
### Author:  [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)
#### Post date: [February 15, 2005, 8:18pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/11 "2005-02-15T20:18:28Z")
> [@Thudlow Boink](#):
>
> Does anyone still measure angles in minutes and seconds, or have they gone the way of the slide rule?
Astronomers still use arcminutes and arcseconds (carefully distinguished from ordinary minutes and seconds, which measure time) when describing the angular size of an object, the angular distance between two objects, or the declination component of an object’s celestial coordinates.
---
### Author:  [@rjk](https://boards.straightdope.com/u/rjk)
#### Post date: [February 15, 2005, 8:33pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/12 "2005-02-15T20:33:57Z")
> [@chappachula](#):
>
> try this example–add two angles : 75 degrees, 45 minutes, 20 seconds plus 25 degrees 15 minutes 10 seconds.
> or add 75.753 plus 25.251
> Which is easier?
101 degrees 30 seconds. And I just read it off, unlike that decimal approximation where you have to convert, add, and convert back to get something close to the true answer. 😛
Of course I was brought up doing DMS, feet and inches, pounds and ounces, and a barrel of ale in London. And I can make change without a cash register too! 🆒
---
### Author:  [@chappachula](https://boards.straightdope.com/u/chappachula)
#### Post date: [February 15, 2005, 8:42pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/13 "2005-02-15T20:42:07Z")
> [@rjk](#):
>
> 101 degrees 30 seconds. 😛
>
> Of course I was brought up doing DMS, feet and inches, pounds and ounces, and a barrel of ale in London. And I can make change without a cash register too! 🆒
Hey, I used to be able to add shillings and pence in my head, too. (ah,…Half-crowns, florins, thrupenny bits—but I never quite understood guineas)
But do you really want to give up decimal currency and go back to the “old ways”?
---
### Author:  [@bump](https://boards.straightdope.com/u/bump)
#### Post date: [February 15, 2005, 8:45pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/14 "2005-02-15T20:45:56Z")
> [@CalMeacham](#):
>
> When I first heard about grads (they were a third angular measure converrsion available on the HP series of calculators) I asked the same question. At the time, I was told that grads were used in the military.
Militaries use mils (milli-radians) as their angle measurement, at least for artillery. One interesting point is that a US mil is1/6400 of a circle, while European ones are 1/6000 of a circle.
---
### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [February 15, 2005, 8:47pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/15 "2005-02-15T20:47:09Z")
I was about to say that, **Bytegeist**. But even astronomers very seldom use degrees, arcminutes, and arcseconds together in the same context. So you might say, for instance, that the Moon has an angular size of half a degree, or if you wanted to be more precise, 31 arcminutes. But one would almost never specify “31 arcminutes and 5 arcseconds”. Such precision is rarely useful in astronomy; the one place where it is useful is in stellar parallax, and there, the angles are all less than an arcsecond anyway, so you’re still not mixing units.
---
### Author:  [@rjk](https://boards.straightdope.com/u/rjk)
#### Post date: [February 15, 2005, 10:04pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/16 "2005-02-15T22:04:13Z")
> [@chappachula](#):
>
> Hey, I used to be able to add shillings and pence in my head, too. (ah,…Half-crowns, florins, thrupenny bits—but I never quite understood guineas)
> But do you really want to give up decimal currency and go back to the “old ways”?
I’ll stick with Canadian dollars and cents, thanks, but I’m sure I could pick up shillings and pence pretty quickly if I had to. Dunno about half-crowns and florins though.
Anyway, the trick with change is NOT to add and subtract, just count. Count enough pennies to reach a round amount, then nickels, dimes, and so on, until you reach the tendered amount. The same idea works with all those other units too.
---
### Author:  [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)
#### Post date: [February 15, 2005, 10:28pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/17 "2005-02-15T22:28:02Z")
> [@Chronos](#):
>
> But even astronomers very seldom use degrees, arcminutes, and arcseconds together in the same context. … Such precision is rarely useful in astronomy; the one place where it is useful is in stellar parallax, and there, the angles are all less than an arcsecond anyway, so you’re still not mixing units.
A fair point. You would seldom see an angle given fully in degrees, arcminutes, and arseconds — not outside of a star catalog anyway. (And who memorizes those?) Still, you have to be familiar with the units, despite their quaint antiquity.
Also, aren’t galaxy surface brightnesses usually given in _magnitudes per square arcsecond_, or something similar?
---
### Author:  [@TJdude825](https://boards.straightdope.com/u/TJdude825)
#### Post date: [February 15, 2005, 11:30pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/18 "2005-02-15T23:30:13Z")
> [@chappachula](#):
>
> Land surveyors (those guys you see on the side of the road with an instrument mounted on a tripod) make hundreds or even thousands of angle measurements during a day’s work.
>
> Grads are great!!!
Good points, but do land surveyors really use grads?
---
### Author:  [@Absolute](https://boards.straightdope.com/u/Absolute)
#### Post date: [February 15, 2005, 11:55pm UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/19 "2005-02-15T23:55:34Z")
Saying that grads are decimal-based doesn’t really explain why they’re useful for anything - I don’t think I’ve ever used arcminutes or arcseconds when dealing with degrees. All through high school and now college, I’ve just used decimals: 78.289 degrees + 41.310 degrees = 119.599 degrees
And really, the choice of 100 grads as a right angle isn’t that much better than the choice of 90 degrees. They’re both arbitrary.
If 360 degrees = 100 grads, then I might agree that there’s some merit to that system. But 400 grads to 360 degrees? What’s the point?
---
### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [February 16, 2005, 9:44am UTC](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217/20 "2005-02-16T09:44:28Z")
Oops, didn’t see this before I posted.
> [@](#):
>
> Militaries use mils (milli-radians) as their angle measurement, at least for artillery. One interesting point is that a US mil is1/6400 of a circle, while European ones are 1/6000 of a circle.
Wouldn’t that mean that neither uses milliradians? A milliradian would be (approximately) 1/6283 of a circle.
[Next page](https://boards.straightdope.com/t/who-measures-angles-in-grads/290217.md?page=2)