How to Zero a Red Dot Pistol Sight (Using Your Actual Groups)
What zeroing actually means
A red dot's point of impact isn't guaranteed to match its point of aim straight out of the box. Zeroing is the process of adjusting the windage (left/right) and elevation (up/down) turrets until your group centers on wherever the dot sits.
Shoot a group first
From a stable rest, at a fixed distance (commonly 10-15 yards/meters for a pistol), fire five or more rounds at one point of aim. A single shot can't tell your own wobble apart from an actual sight offset — you need a group.
Measure the offset
The number you need is the distance and direction from your point of aim to the group's center — the same thing this site's accuracy and bias figures describe (see Accuracy vs. Precision). Manually, that means a ruler on the target. Range Tracer reads it straight off your target photo.
Dial it out
Most red dots list a click value (e.g. 1 MOA per click). Convert your measured offset to MOA at your zeroing distance (see What Is MOA), divide by the click value, and adjust that many clicks in the direction that moves point of impact toward point of aim.
Confirm, don't assume
Shoot another group after adjusting. A single adjustment rarely lands exactly on zero the first time — treat zeroing as iterative, not a one-shot fix.
Measure it, don’t guess
Log a session and Range Tracer calculates accuracy, precision, and bias automatically.