What is interesting is some will find MIL easier to do in their head than MOA and vise versa. Hence the reason I stated what I did. Find the system you like best, make sure the math is doable for you and then go with it. The reality is though that the math on either system is plenty doable with a little practice.
There are 2 formulas for ranging that are both pretty simple and very similar.
MOA- target size in inches / MOA reading x 100 = distance to target in yards
MIL- target size in inches x 27.8 / MIL reading= distance to target in yards.
One can also use target size in yards x 1000 / MIL reading = distance in yards
No trig needed!
I still think guys get too wrapped up in the math of it all. Unless you are ranging you shouldn't be using any math at all, just measure with the reticle and make the appropriate adjustments. If ranging is needed then there are simple basic math formulas that will get the job done.
This is so true. Both methods are terribly easy and will accomplish the same thing if you are actually using the reticle for ranging. The problem with ranging with the reticle is that often times you don't know the exact size of your target. You have approximations of size, for instance a mule deer might average 19" from brisket to back bone. What if he is actually 22"? Either way, you should be able to go into a hunt with the first half of the equation answered already. All you have to do is divide by the measurement of either MOA or mil from your scope.
let's do a quick exercise both ways with a deer 19" brisket to backbone deer.
Let's say you measure his size at 4 MOA in your scope
MOA: 19 inches x 95.5 / 4 MOA = 454 yards away
You can also multiply the inches by 100, but 95.5 is the more accurate measure since MOA is not a direct converison to inch.
For mil you measure a 19" buck to be 2 mils. (19" converted to yards is .53 yards.)
Mil = .53 yards x 1000 / 2 mils = 265 yards away
These are extremely simple calculations and both will work if you're in a pinch without a rangefinder.
Wouldn't that technically be IPHY while MOA is x" / MOA * 95.466 y/" ?
You are correct, but it's still darn easy. If you actually plan to measure with your scope you should be able to go into a hunt with the first half of the calculation done because, no matter what, you are dealing with approximations of animal size.
I know they are exactly the same as MRAD. The whole 10 based system is why people relate MRAD as metric system which it isn't. It suits metric perfectly but isn't a SI standard unit.
You are correct, MIL and MOA are both angular measurements not imperial or metric. Hence, the reason I point out that guys get too caught up in the math of it all. As I have stated many times, guys really shouldn't use math at all for most of the reasons that a reticle will be used. That is except for ranging where then a formula is necessary.
The problem is though, that trainers, manufacturers, and advertisers all relate MOA to imperial and MIL to metric because the numbers are very close and work if one is to do the math. Plus everyone is trying to find a marketing advantage. And MOA makes more sense to consumers in the US which is why I think it has been more widely popular here. The opposite is true in Europe. In reality the reasons we choose MOA or MIL likely don't matter much and the real differences or advantages of one over another are ignored.
For those of us who use metric as a base, easy measurements are either 1m (upper torso of a man, height of the average whitetail etc) or 30cm which is almost equal to 12" and approximate the size of a human head for example. If you can find targets that size on your game, mils becomes a VERY easy calculation.
For you example, your 19" estimate is very close to 50cm, an easy mil calculation again.
0.5m * 1000 / 2 = 250m
Even if you went with straight inch to m conversion, calculating distance is still easy:
0.4826m * 1000 / 2 = 241.3m ( = 263.888 yd)
There is always going to be error margin on both methods. First is the estimation of target size but with inches and yards you also have a error margin coming from the conversion. 19/36 = 0.53 is a rounded number from 0.52777...... Then add the error margin from the estimation of the mils on the reticle...so all I can say is practice, whatever system you use!
I think we're on the same page here and I don't disagree with you a bit. My point here is that even by using the most accurate figures in calculation, you are still approximating the size of the animal. 50 cm or 19 inches isn't going to make a great deal of difference. But if you go in thinking the approximate size of a mule deer buck is 19" and the buck you have in your scope is actually 22" then the range is going to be off significantly.
It's best to reserve reticle measurements for pinch situations when the rangefinder isn't working or not available.