John McPhee on quick range estimation

Range Estimation, unknown distance, you name it, and this is one of the many skills that is necessary for most any professional Infantryman in the world. All of their weapon systems depend on not only knowing the range to an enemy target, but much more importantly, knowing the correct range to that target. Whether the soldier is employing small arms or artillery, range plays a crucial factor. But how do you make an accurate range call? Snipers have their mil dots, American troops have their RCOs, and Forward Observers know how to use their stadia lines in their binoculars. The problem with most of these methods, when it comes to range estimating enemy personnel, is that the methods are usually based on the fact that the target isn’t moving, and is standing still. Most of this takes into account that the average shoulder width of a man is 19.5 inches as well. However, human beings for the most part, don’t stand still long enough for this precise calculation to occur. Enter John McPhee and his innovative method of range estimation out to 600 meters, using just what human features look like at certain distances. I’ll outline what he does with each distance below, but about the only gripe I have about this is that he doesn’t specify what scope power this system uses, apart from him mentioning this can be used with the naked eye. For example, using a spotting scope, I’m sure some of these features don’t stand out at these ranges because of the magnification.

100 meters- Recognize a face, see what they look like

200 meters- No face, cannot distinguish facial features

300 meters- No hands, soldier can distinguish what the enemy is doing, but cannot make out individual fingers or the entire hand.

400 meters- The head cannot be distinguishable, in fact it looks like they don’t have one at all.

500 meters- Cannot see individual legs, especially the light between their legs, an enemy is moving, but he is moving as a whole, without legs to the soldiers eye.

600 meters- Humans look like little triangles in shape. He says “A fat little triangle”.

He doesn’t go beyond 600 because humans are much harder to even distinguish past that distance, in addition this method is to be used quickly, presumably while under fire. Not that an enemy past 600 can be a threat, but it becomes increasingly unlikely with small arms. And if they are that far out anyways, a soldier will probably have the luxury of time to use conventional range estimation methods.


Infantry Marine, based in the Midwest. Specifically interested in small arms history, development, and usage within the MENA region and Central Asia. To that end, I run Silah Report, a website dedicated to analyzing small arms history and news out of MENA and Central Asia.

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  • Dave Curtis

    All of these are with no magnification. If using optics, multiply the range on his chart by the power used.

  • MonoChango

    One would assume that you apply the X factor to all these calls. If you are looking through a 2X scope then the same apply but double the yards. Thus at 1000 yards, you will not see light from between a running mans legs.

    • JumpIf NotZero

      Nice thought, but not how it works exactly. The acuity from X to Y is not linear. Comparing things at 800y to 1000y looks a lot closer in size and detail than things 100-300y apart.

      Just because you 2x’ed your view doesn’t change that. Far away things are still far away. You have a lot more refraction and things in the way to add to that.

      To really double the range he’s giving an example of you’d need more than 2x, but I don’t know how you’d determine the value needed. I suppose it would relate to human resolution which I suspect is logarithmic.

      • Logic Rules

        Actually, I think MonoChango may be correct, though JumpIf NotZero is correct with what I think he’s trying to say. It’s just that the two may be talking about two different things.

        JumpIf NotZero seems to be implying (correctly) that even though the difference between 100yds and 300yds is the same as the difference between 800yds and 1,000yds (the difference being 200yds), the difference in angular size (how large they appear relative to each other) will not be the same when comparing 100yds to 300yds and 800yds to 1,000yds. The reason for this is that angular size depends on the proportional difference (ratio) in distances, not the numerical difference in distances.

        The numerical differences below are the same:
        300 – 100 = 200
        1,000 – 800 = 200

        The proportional differences (or ratios) below are NOT the same:
        300 / 100 = 3
        1,000 / 800 = 1.25

        JumpIf NotZero’s statement “comparing things at 800y to 1000y looks a lot closer in size and detail than things 100-300y apart” is correct, but it’s also correct to say “comparing things at 400y to 500y looks a lot closer in size and detail than things 100-300y apart.” But one would be wrong to think that the proportional difference between 1,000yds and 800yds is different than between 500yds and 400yds. That’s because the ratios are the same (1,000 / 800 = 1.25 and 500 / 400 = 1.25).

        MonoChango seems to be multiplying each range by 2 such that the ratios remain the same, and this technique seems to be correct. He is not adding 200yds to each number, which would cause different ratios. For example (assuming a 2X optic):
        100 x 2 = 200yds Recognize a face
        200 x 2 = 400yds No face
        300 x 2 = 600yds No hands
        400 x 2 = 800yds Head cannot be distinguished
        500 x 2 = 1,000yds Cannot see individual legs
        600 x 2 = 1,200yds Humans look like little triangles in shape

        The proportional differences between ranges among the two sets numbers would be the same:
        300 / 100 = 3
        600 / 200 = 3
        500 / 400 = 1.25
        1,000 / 800 = 1.25

        • Zebra Dun

          Now I have a headache!

      • AirborneSoldier

        Sir, we are talking quick range estimation, under fire.
        All the egghead stuff is an epic fail in the mud, scared for your life.


    That truck window looks like the menu at the bunnyranch…

    • Vhyrus

      I’m considering making a new account just to upvote you again.

    • JumpIf NotZero

      Ha. Sort of an inverse relation to prices… so I assume.

    • Poplicola Publicola

      So does that mean that the girls working at the bunny ranch are all amputees?

      I once knew a girl who only had one leg that said she was going to get a job at the downtown IHOP!

      • heathjayman

        I bet her name was Eileen. Unless she was Japanese, in which case it would be Irene.

        • Poplicola Publicola

          Ha ha ha

    • Lonnie

      Or Donna’s in Wells!

  • The_Champ

    Very similar system was taught to me in the Canadian Forces.

  • JumpIf NotZero

    I got LASIK years ago, can read of the 20/15 line reliably. I don’t
    think the chart will work for me an coke-bottle-johnny the same way.

    I like the idea quite a bit, but I feel that it’s too limited to someone’s specific acuity over another. I can think of a specific bridge that I know is exactly 1000y away from a 6th story office window, the people on that bridge are not “fat little triangles”.

    • Tahoe

      That is an interesting and oddly specific range to know…no, don’t tell us about how you know that. We don’t want to be accessories 🙂

      I like this chart, but I agree with several here that it completely depends on the shooter’s visual acuity. For that matter, I had better than 20/20 when younger, but I’ll bet it’s less now – so the values change.

      The key is to use the _system_ for yourself – go out and figure out those items and their ranges. At what range can you cease to distinguish a face? Hands? Head? Etc. Then you know the relevant ranges for yourself.

      • JumpIf NotZero

        Haha! Well, you’re not too far off. I was at a class doing long range dope and shooting at 1000y-1200y. The next week I was looking out an office window and saw a bridge I guessed to be “about that far”. Hopped on google earth and used the measurement tool, sure enough 1000y +/- maybe 20y.

        Yea, determining this for yourself would be key.

      • AirborneSoldier

        Are you guys saing people dont wear glasses? Better get something or you will die. Cant hit what ya cant see. Keep it simple ppl!

  • VF77

    I like it. Good info, derived from experience. Seems like a pretty simple method to be able to employ. Haven’t seen anything from the S.O.B McPhee in a while…

  • Major Tom

    I wouldn’t call people at 600+ meters “fat triangles”. More like “standing ovals”.

    I say so because in Colorado you have very clear air in daylight owing to low humidity and particulates (especially in the mountains) which means you can get very long sightlines with very little obscuration or diffraction of objects. Meaning on a good day you can see a moving semi-tractor trailer truck on a road 20 miles (~32 km) away. With motion and/or color contrast like wearing an orange hunting poncho at the edge of a woodline in a meadow you can see a man-sized target at 2000 meters. At that range he’s barely bigger than a dot. At 1000 meters he becomes shaped like a thin 0 of sorts.

    The rest of the quick and dirty guide is for the most part accurate.

    • JumpIf NotZero

      Yea, that was weird to me too. I know of a 1000y and 1250y view I see people at all the time. And a 2000y that I see elk at from my office, they’re small and you need a spotting scope to really see them, I can tell what they are.

      • Zebra Dun

        Experience tells you what they are. Even if you cannot actually tell what they are.
        Like movement in gray up a tree at 25 meters is a squirrel and at 50 meters it’s a forest with a shape that you know is a squirrel.
        Swaying back and forth, tanned and yellow with polka dots at 300 meters is a Babe in a bikini for sure. IF your on the beach.

  • RealitiCzech

    I suspect this depends a bit on your vision. For me:
    50 yards – I can make out a face
    100 yards – yup, that’s a bipedal creature of vaguely human proportions
    200 yards – probably a human, or a very civilized bear, possibly wearing a top hat
    300 yards – I think I see something moving, it might be more than just bushes
    400 yards+ – unless it’s Hannibal and his elephants, I’m not seeing anything more than Stevie Wonder.

    • tsubaka

      with a scope? or naked eye?

    • Zebra Dun

      Reality and old age bite every time LOL

  • politicsbyothermeans

    600 meters: can easily make out PKM owning your unit

    • Zebra Dun

      1000 meters can visually acquire the Tank lasing your butt.

  • tincankilla

    is there a comparable shorthand for Mule Deer?

    • Zebra Dun

      Can see spike to it may be a house wife hanging out white sheets?

  • AirborneSoldier

    Good article. No bs, to the point, and true.

  • Zebra Dun

    Yup, learned from Gunny in my callow youth.

  • WEK

    See Range Estimation CMC-30 Combat Marksmansip Coaches Course 8/12/08 by USMC Weapons Training Battalian, Quantico, VA.