Archery Point of Impact Shift Calculator

How Archery Point of Impact Shift Is Calculated

When you adjust your bow sight, the arrow’s point of impact moves by a calculable amount. Understanding this relationship lets you dial in your sight precisely and efficiently.

Sight Movement Formula: Sight Movement = (POI Shift / Distance to Target) × Sight Radius

Where:

• POI Shift = how far your arrow landed from center (mm or inches)
• Distance to Target = shooting distance (same units as POI shift)
• Sight Radius = distance from sight pin to arrow’s pivot point (typically 400–600mm for recurve)

Golden Rule of Sight Adjustment: “Follow the arrow”, meaning move the sight in the same direction as the point of impact shift.

• Hit low → move sight down
• Hit left → move sight left

This feels backwards the first few times and it is worth knowing why it is right. Moving the pin down forces you to raise the bow to put the pin back on gold, and raising the bow raises the arrow. The sight chases the error, and the shot corrects itself.

Worked Example: Target at 18 meters (18,000 mm). Arrows hitting 60mm left. Sight radius = 500mm:

• Sight movement = (60 / 18,000) × 500 = 0.00333 × 500 = 1.67 mm to the left

Click Values on Sight: Most competition sights have adjustment clicks of 0.5 to 1.0mm of sight movement. With a 500mm sight radius at 18m, 1mm of sight movement is a 36mm shift at the target, because 18,000 ÷ 500 = 36.

Why the calculator asks for a click value instead of a sight radius

The formula above needs the sight radius, but you never have to measure it. A click value quoted at a known distance already has the radius baked into it: if one click moves your impact 1.8cm at 18m, that single fact carries everything about the geometry of your bow. So the calculator asks for the number you can actually measure on a target face, then scales it.

Distance Scaling: One click of the sight is a fixed angle, so the further you shoot the more ground that angle covers. A click worth 1.8cm at 18m is worth 7.0cm at 70m, nearly four times as much. The practical consequence: a group that is 10cm out at 70m needs far fewer clicks than the same 10cm error at 18m, and archers who forget this routinely overshoot the correction at long range and end up chasing their group across the face.

Recurve vs Compound: Longer sight radii give finer control: the same 1 mm of sight movement shifts impact less, so each click is a smaller, more precise correction. Fixed pins (compound): set each pin at a specific distance and switch between them.