The short answer: 3 MOA is the right default for a pistol — fast enough to find under pressure and small enough to aim with at any realistic pistol distance. Go to 2 MOA if the gun is for competition or precision work, and to 6 MOA or larger if it is for speed inside ten yards or for a shotgun swinging at something moving. If you genuinely cannot decide, buy a circle-dot reticle like the Holosun HS507C-X2: a 2 MOA dot inside a 32 MOA ring gives you both references in one window and you can switch either off.
What MOA actually means here
MOA is minute of angle — one sixtieth of a degree. At 100 yards one MOA subtends 1.047 inches, which everyone rounds to one inch because the difference does not matter at a shooting range. Angles grow with distance, so a dot of a given MOA size covers a proportionally bigger area the further out you look.
That is the whole calculation. Here is what each common dot size covers, rounded:
| Dot size | At 10 yd | At 25 yd | At 50 yd | At 100 yd |
|---|
| 2 MOA | 0.2 in | 0.5 in | 1.0 in | 2.1 in |
| 2.5 MOA | 0.3 in | 0.7 in | 1.3 in | 2.6 in |
| 3 MOA | 0.3 in | 0.8 in | 1.6 in | 3.1 in |
| 4 MOA | 0.4 in | 1.0 in | 2.1 in | 4.2 in |
| 6 MOA | 0.6 in | 1.6 in | 3.1 in | 6.3 in |
| 32 MOA circle | 3.4 in | 8.4 in | 16.8 in | 33.5 in |
Read that table once and most of the internet's arguing stops. At 10 yards a 6 MOA dot covers six tenths of an inch — it is not hiding anything you were going to hit. At 100 yards it covers over six inches, which hides most of a target's scoring area.
The real trade is acquisition speed, not precision
A bigger dot is easier to find. That is not a feeling, it is why it exists: more emitted area means your eye picks it up with less searching when the gun comes up and your head is not perfectly behind the optic. Under a timer, or on a bird, that difference is measurable in a way that half an inch of coverage at 25 yards is not.
A smaller dot is easier to aim with, and — the part people miss — easier to see crisply if your eyes are good. It also shows you your own wobble, which is useful information and occasionally discouraging.
So the honest framing is: buy the smallest dot you can find fast, for the kind of shooting you actually do.
By what the gun is for
- Carry pistol: 3 MOA. This is the industry default for a reason. It covers under an inch at 25 yards, which is far finer than defensive accuracy demands, and it is quick to pick up from an imperfect presentation. 6 MOA is a defensible choice if your practice is all close and fast.
- Competition pistol: 2 to 2.5 MOA, or a circle-dot. You are shooting partial targets at distance against a timer, and you want both. Big-window optics with a small dot exist specifically for this.
- General-purpose rifle or carbine: 2 MOA. At 100 yards that is two inches. Anything bigger starts covering targets you can otherwise hit.
- Shotgun: 4 MOA or larger, or a circle-dot. Speed on a moving target, and the dot's size is irrelevant against a shot pattern — except for turkey and slugs, where you want the small dot inside the ring. The shotgun page goes through that properly.
- Concealed carry on a small slide: 3 MOA, and check the footprint first. Compact slides are usually cut for a small footprint and no adapter makes a small footprint bigger. The footprint constrains your choice more than the dot size does.
If the dot looks like a smear rather than a dot
Then dot size is the wrong variable and you are solving the wrong problem. A red dot that appears as a comet, a starburst or a smeared line is the classic presentation of uncorrected astigmatism, and buying a smaller dot will make it worse rather than better. A larger dot, a green emitter or a different reticle shape frequently helps. The astigmatism page explains why and what actually works, and the red-against-green comparison is here. Neither page is medical advice and both say so.
What to check before you buy, in this order
- Footprint. What your slide or rail is cut for. This eliminates most of the market before dot size is even relevant.
- Open or enclosed emitter. Weather and pocket lint, not optics. Covered in full here.
- Dot size. The table above.
- Brightness range and auto behavior. Whether it is usable against snow and against a dark treeline, and whether it wakes up when you pick the gun up.
Notes on the numbers
Published dot size is nominal
Manufacturers state a nominal MOA figure and the apparent size varies with brightness setting and with your own eye. A dot turned up to maximum against a bright sky will look and behave bigger than its stated size. Turn the brightness down until the dot is crisp — most people run theirs far brighter than they need.
A circle is not a dot
A 32 MOA ring is not an aiming reference at distance, it is an acquisition aid. Use the ring to find the target fast and the dot inside it to aim. On a defensive gun at close range the ring alone is enough.
Dot size does not change your zero
A bigger dot does not move the point of impact, it just makes it harder to see precisely where that point is. Zero with the brightness you actually use and the dot centered on the same part of the target every time.
How these were picked
I haven't handled these. Here's what I did instead.
Everyone in this category says they tested twenty of these. I haven't tested any, and I say so. What I do instead: read the manufacturer's manual and published specification, compile the numbers that decide the purchase, do the arithmetic in the open, check the live price, and name one product to skip. The scores above are judgments from that research against a published rubric — they are not measurements I took, because I do not have a lab and I am not going to pretend otherwise.
