Target size example is 24 inches. This is a known. You have to know the size of the target. 24” is a common size for an elk cow shoulder to brisket. It could be any number in inches.

Makes sense,
I got lost in the part where I convert inches to meters.
As far as knowing what to adjust to
I would need to know my bullet drop at specific distances correct?

You’re getting out over your skis. You have to be able to find a range before you can shoot that range. So make sure you understand the formula, then practice ranging imaginary targets.

Well formula away, or use a "mil wheel" or "mil slide rule" and then ya don't have do fractal math on the fly! Or like we used to say zap em, dial em, do em! (Zap em = range finder )

This could be because you're still trying to figure out why .0254 is there and why you're converting inches to meters.
Rehash on the formula:

Range = METERS (actual target size) x 1000 ÷ mils (size of target measured with mil reticle)

ONE INCH is .0254 METERS. That is why the .0254 number is there. So you can convert inches to meters. You have to convert inches to meters so you can finish the formula and get a range to a target. If you can't do the formula, you will never be able to use a mil reticle effectively, at least for ranging.
So 10 INCHES = .254 METERs. 28 INCHES would be .711 METERS. All done on your calculator (or long math or whatever).

I was gonna hold off on this, but it's the same formula, just kinda removes one step.

Range = METERS (actual target size) x 1000 ÷ mils (size of target measured with mil reticle)

AGAIN: Once the formula is understood, you just need to know the size of things.
So write like this:
Removing the .0254 and the 1000, and multiplying TGT size by 25.4

RANGE = Known TGT Size in (INCHES x 25.4) ÷ TGT Size measured in mils

24" target

You milled at 1.7 mils

24 x 25.4 = 609
609 ÷ 1.7 = 358
range is 358 meters

Once the formula is understood, you just need to know the size of things. you just need to know the size of things. you just need to know the size of things. you just need to know the size of things.

If you don't know the approximate size of the target, whatever it is, you won't be able to range it. So you need to find something that you know the size of.

Another example:

All Ford Raptors have 35" tires stock. They are also 20 feet + long and 6 feet ish tall. but at angles and such, it won't be accurate. So use the tire.

You're sitting in your stand, you see a raptor far off, and you want to see how far away it is. You mil the tires several times and you get .8 mils

35 x 25.4 = 889
889 ÷ .8 = 1111
The Raptor is 1,111 meters away

I am posting these in a specific order so you can learn them/understand. You can mil all day long and it'll mean nothing unless you know how to find the range. Actual milling a target takes practice too.

Well formula away, or use a "mil wheel" or "mil slide rule" and then ya don't have do fractal math on the fly! Or like we used to say zap em, dial em, do em! (Zap em = range finder )

That's not part of this class, and it's not a hard formular either. How many people carry around a mildot master or mil slide or even a quality LRF? Almost nobody.

Once you have figured out the formula, you can get a given factor that is ALWAYS the same for a known target size.

Formula:
RANGE = Known TGT Size in (INCHES x 25.4) ÷ TGT Size measured in mils

24" target milled at 1.7 mils, you get this: The given factor for a 24" target is 609. No matter what, it is 609, and will always be 609. 609 WILL always be the number that is divided by a mil measurement if the target is 24".

24 x 25.4 = 609
609 ÷ 1.7 = 358
range is 358 meters

Common sizes seen:

40"/1 meter (human torso from beltline to top of head) factor is 1016/990
18"/.5 (19.5) meter (human shoulder width) factor is 457/495
24" cow elk shoulder to brisket (est) factor is 609
12" Human head (trapezius to top of head) factor is 304
10" width of human head factor is 254
36" truck tires; avg window width factor is 914

You can make those into a card, and divide them by the mil measurement to get the range. Or whatever common known size you have around you. Regardless, if you are milling a target for a range, you have to know the size no matter what.
So your card taped to you rifle or in your hat would look something like this:

Milling a target
Pic demonstrates using a milgrid reticle to mil a 12" target. Use a 1 mil start (in this case at the top) and read the opposite edge. In this example, the T3 reticle has a section of .1 mil increments to get a more precise measurement. If yours doesn't have refined subtensions, like .1 mil or .2 mil, you split it or estimate.

Now that you read everything from the beginning (except the S-posting) and understand the formula and the progression to get a simple solution, you can now make a simple range card based on a given size of target and mil measurements.

18” range card Factor is 457; 457÷ mils gives your distance in meters; 18” is default EST for deer shoulder to brisket. If the deers are smaller or larger in your region, readjust.