Red dot size at distance calculator
Quick answer: a red dot measured in MOA covers a set fraction of the target that grows with distance. One MOA is about 1.047 inches at 100 yards, so a 2 MOA dot covers about 2.09 inches at 100 yards and a 6 MOA dot about 1.57 inches at 25 yards. Enter your dot size and a distance below to see exactly how many inches or centimeters the dot blankets. A bigger dot is not less accurate, it just hides more of the target, which is why close-range carry favors 3 to 6 MOA and precision favors 1 to 2 MOA.
Calculate how much a dot covers
Turn on JavaScript for the live result. The reference table and worked example below give you the same math by hand.
Dot size is an angle, so a single dot covers more of the target the farther away it is, but it never changes the optic's mechanical accuracy. Use this to picture how much of a target your dot hides at a given range, then pick a size with MOA dot size: 2 vs 3 vs 6 MOA.
What each dot size covers at each distance
This is the reference the calculator uses, in inches. One MOA covers about 1.047 inches at 100 yards and scales linearly, so every value here is the dot's MOA times the 1 MOA figure for that range.
| Distance | 1 MOA | 2 MOA | 3 MOA | 6 MOA |
|---|---|---|---|---|
| 25 yd | 0.26 in | 0.52 in | 0.79 in | 1.57 in |
| 50 yd | 0.52 in | 1.05 in | 1.57 in | 3.14 in |
| 100 yd | 1.05 in | 2.09 in | 3.14 in | 6.28 in |
| 200 yd | 2.09 in | 4.19 in | 6.28 in | 12.57 in |
| 300 yd | 3.14 in | 6.28 in | 9.42 in | 18.85 in |
Metric: 1 MOA covers about 2.908 cm at 100 m, so a 2 MOA dot covers about 5.82 cm at 100 m. One MOA is a hair larger than 1 inch per 100 yards, which is why shooters round it to "1 inch at 100 yards" for quick mental math.
Worked example (do it by hand)
Take a 3 MOA dot at 50 yards. One MOA is 1.047 inches at 100 yards, so at 50 yards it is about 0.52 inches, and three of them is about 1.57 inches. At a close defensive distance of 15 yards, the same 3 MOA dot covers only 3 times 1.047 times 0.15, about 0.47 inches, less than half an inch, so it is plenty precise for a self-defense target. Push it out to 200 yards and it blankets about 6.28 inches, which starts to cover a small target, the reason distance shooters prefer 1 to 2 MOA.
FAQ
How big is a 2 MOA dot at 100 yards?
A 2 MOA dot covers about 2.09 inches at 100 yards, because 1 MOA is about 1.047 inches at 100 yards and the dot is two of them. It scales with distance, so the same 2 MOA dot covers about 1.05 inches at 50 yards and roughly 4.2 inches at 200 yards. That is why a 2 MOA dot is the choice for precision and distance work: it hides very little of the target.
How big is a 6 MOA dot at 25 yards?
A 6 MOA dot covers about 1.57 inches at 25 yards. Because it is an angle, that "huge" 6 MOA dot only blankets about an inch and a half at a typical defensive pistol distance, which is why carry shooters run a 6 MOA dot happily: it is fast to find under stress and still precise enough up close. At 100 yards the same dot covers about 6.3 inches.
Does a bigger MOA dot mean it is less accurate?
No. The optic and its mechanical zero are unchanged; a bigger dot simply covers more of the target, so it can hide a small aiming point at distance. Up close the difference is tiny (a 6 MOA dot is about 1.5 inches at 25 yards), so a big dot is not less accurate for close, fast shooting. It only costs precision when you are aiming at something smaller than the dot covers, which is why target and rifle shooters prefer 1 to 2 MOA and carry shooters accept 3 to 6 MOA. See MOA dot size: 2 vs 3 vs 6 MOA.
How do you calculate the size a dot covers at a distance?
Multiply the dot size in MOA by what one MOA covers at that range. One MOA is about 1.047 inches per 100 yards, so coverage in inches equals MOA times 1.047 times (distance in yards divided by 100). For a 3 MOA dot at 50 yards: 3 times 1.047 times 0.5, which is about 1.57 inches. In metric, one MOA covers about 2.908 cm at 100 meters, so coverage in cm equals MOA times 2.908 times (meters divided by 100).
What size red dot should I get?
Match the dot to the job. A 1 to 2 MOA dot is best for precision and distance (rifles, target work, an AR at range) because it obscures the least. A 3 to 4 MOA dot is a versatile middle for a general-purpose pistol or carbine. A 6 MOA dot is fastest to pick up under stress and ideal for close-range carry, where its larger size at pistol distances is not a real precision cost. Some sights let you switch sizes or use a circle-dot to avoid the compromise.
Related: MOA dot size (2 vs 3 vs 6 MOA) · MOA vs MRAD · MOA/MRAD adjustment calculator · mil dot ranging calculator · how to sight in a red dot · best red dot sights 2026.