Mil dots explained simply

Post Reply
User avatar
Senior Moderator
Senior Moderator
Posts: 136
Joined: Fri Jun 02, 2017 7:00 pm
Age: 71
Location: Sacramento area, California

Mil dots explained simply

Post by Popeye »

From spystyle April 2006

Here is the simplest explanation of mild-dots I have ever read:


The simplest way is:

(size of object in millimeters) / (size of object in mils) = range in meters.

Just teach yourself to use the metric system.

Average man = 1750 mm
Beer can = 130 mm
Kneeling man = 1200-1250 mm
Human head (width) = 150 mm

The beauty of the mil dot system is that it doesn't matter what units you use, as long as you are consistent. If the spacing of 1 mil through the scope is X units high, then it is 1000 X units distant. The units can be feet, yards, or meters, it doesn't matter. If you want the answer in yards, think of how many yards one mil subtends.

Example: If one dot spacing is 0.5 yards (18") high, then the distance is 1000 * 0.5 = 500 yards away. A 6' tall person would subtend 4 dots at 500 yards, or 2 dots at 1000 yards. If you want the answer in meters Mr Hugh's' advice is fine. The metric system has advantages at times.

The problem with the mil dot system (as compared to a laser rangefinder) is in estimating the actual size of the target. Sometimes it's easy, sometimes not. Mil dot accuracy in terms of percent range accuracy will be the same as the error in estimating the target size. If you think a man is 6' tall and he's 2 mil high in the scope, but he's really 5'6" you will think he's at 1000 yards when in fact he's at 917 yards. If you're shooting a .308 you will shoot high by about 80 inches. Not even close, and that isn't considering any other error sources. At ranges 400-700 yards the mil dot system works pretty well. Closer than that you probably don't need anything other than an eyeball estimate (with a little practice).

Lou Boyd

(end quote)

The original article is here:

Here is a metric/standard conversion calculator:


The difference between a Communist and a Socialist is; the Socialist doesn't have all the guns yet

Posts: 240
Joined: Fri Jun 09, 2017 5:45 pm
Age: 60
Location: Montgomery, Alabama

Re: Mil dots explained simply

Post by professrh »

Thanks, Popeye.

This beats the "hunter hangover" system by a long shot.



User avatar
Global Moderator
Global Moderator
Posts: 98
Joined: Sat Jun 03, 2017 6:12 pm
Age: 46
Location: Toronto, Canada

Re: Mil dots explained simply

Post by samsplacci »

I have second focal plane Bushnell fixed 10 x 40 scopes with DOA reticle. I bought a mil - mil reticle in first focal plane, and what a difference. The 2 advantages were: 1) zero of the scope and 2) estimating the distance of the object based on size at a distance using the reticle and how many mils it occupies.

I am now a believer in mil - mil and first focal plane. I believe Primary Arms, Falcon and SWFA offer affordable and reliable FFP scopes. I have a Falcon M18. 4 - 18x50 and it cost me $400 Canadian Pesos.

Posts: 142
Joined: Sun Jun 04, 2017 6:29 pm
Location: Lee's Summit, MO

Re: Mil dots explained simply

Post by HectorFuego »

I believe in the KISS principle. Mil-Mil scope with 1st focal plane. No matter what scope magnification the scope is, it will always yield the correct adjustment.

If you can't kill it with a 30-06 you ain't in North America.
The first rule of intelligent tinkering is, "Save all the pieces."
It'll feel better when it quits hurtin'.

Post Reply

Return to “Optics and Optics Mounts”