True MOA
The exact value of a minute of angle, roughly 1.047 inches at 100 yards, rather than the convenient rounded inch that many shooters use instead.
True MOA uses the real geometry of a minute of angle, which subtends about 1.047 inches at 100 yards because a full circle of 360 degrees divides into 21,600 of these tiny slices. That extra 0.047 inch per hundred yards seems trivial up close, yet it is the honest number that ballistic software and properly calibrated turrets are built around. Optics makers who advertise MOA adjustments are usually working from this true value rather than a rounded one.
The contrast is shooter’s MOA, which rounds the same angle down to a flat inch for easier mental math. The difference matters most at distance, where 1.047 versus 1.000 inch per hundred yards adds up to a meaningful error on the target. When you confirm that each click on your turret tracks the true value, your dialing stays honest across the full range, which is central to the MOA vs mil comparison.