Optic Zeroing Simulator
Measure where your group landed, choose the click value from your optic, and work through the same group, dial, and re-aim sequence you use at the range. Look through the optic in 3D, switch to the bench view to see why the reticle moves opposite the impact, or start a range session and zero a hidden offset from scratch.
Interactive zeroing bench
Look through the optic, turn the same two adjustments you use at the range, then re-aim and preview the next group. Choose Range to view the selected distance, Explain for the enlarged diagram, or Inspect target for a close-up.
Session setup25 yd · 1 MOA/click · 2 in low, 1 in right
Measured group
The reticle is centered on the aiming point. The five-hole group shows the measured miss.
Live result
Original group: 2 in low, 1 in right
After applied clicks: 2 in low, 1 in right
This predicts correction from one measured group. Calculator holes are illustrative, and range-session spread is a plausible mid-range value for each optic class; shooter error, ammunition, cant, parallax, loose hardware, and trajectory at another distance are not modeled.
Shoot a real group
Use a stable rest and one aiming point. Fire 3–5 rounds, then measure from the bullseye to the center of the group.
Dial the named direction
Enter the miss and apply the recommended whole clicks. UP, DOWN, LEFT, and RIGHT describe where the next group should move.
Confirm before finishing
Re-aim at the same point and fire another group. Record the final zero only after two centered groups agree.
What the simulator calculates
Every optic type uses the same angular geometry. One MOA spans 1.047 inches at 100 yards, while 0.1 MRAD spans 0.36 inch at 100 yards or exactly 1 centimeter at 100 meters. The simulator divides the measured miss by one click's movement, rounds to the nearest whole click, and preserves the small predicted residual.
Use the MOA and MRAD calculator for direct angular conversions, the target photo scorer to measure a photographed group, and the optic zeroing guide to choose a distance and confirm the finished zero.
Frequently asked questions
Which direction should I dial when my group is low and right?
Dial elevation up and windage left so the point of impact moves toward the point of aim. Turret arrows normally describe point-of-impact movement, but the physical direction you turn a knob varies by optic. Follow the UP and RIGHT markings on your exact sight.
Why does the reticle move opposite the point of impact?
The adjustment changes the reticle's angle relative to the bore. With the firearm held still, the reticle appears to move toward the old group. When you re-aim that reticle on the bullseye, the bore points the other way and the next group moves toward center.
Is dot size the same as click value?
No. Dot size describes how much target the aiming dot covers. Click value describes how far one adjustment moves the point of impact. A 3 MOA dot can still use 1 MOA, 0.5 MOA, or another click value.
Does scope magnification change how far one click moves impact?
No. A turret's angular click value stays the same at every magnification. Magnification can make the target and wobble look larger, but a 0.25 MOA click remains 0.25 MOA.
Can this simulator confirm my zero?
No. It predicts the correction from a measured group. Fire another 3–5 shot group at the same distance after dialing, then confirm again at the distance where you plan to use the optic.
What does the range session practice mode simulate?
The bench hides a bore offset, fires a five-shot group with realistic spread for that optic class, and lets you measure the group, dial the turrets, and fire again until a group centers within one click or one MOA of the aiming point. It teaches the measure, dial, and confirm loop without spending ammunition.
What does a 20 MOA base do to my zero?
A 20 MOA base tilts the scope down toward the muzzle by 20 MOA. The zero still needs the same bore-up angle, so after zeroing the erector sits about 20 MOA lower in its travel than it would on a flat base, which leaves that much more up-travel for dialing distance. If the base is steeper than half the scope's total travel plus the zero angle, the scope cannot dial low enough to zero at all. The scope presets show the erector position and the remaining travel once you enter the base cant and the scope's published elevation travel.
How do Range and Explain differ?
Range places full-size paper at the selected distance. The paper appears smaller as you move it farther away. Explain fits the paper to the sight picture and uses an enlarged board on a short bench lane, with labeled sight and bore lines. Inspect target opens a close-up in either mode.