Bow Sight Tape Calculator

What a sight tape does

A sight tape is the strip of paper or printed scale that runs alongside your bow sight slider. You set your zero pin (often 20 yards), then the tape tells you exactly where to slide the sight for any other distance, 40, 60, 73, without needing a separate pin for every yardage. Field archery and 3D shooting both depend on it. A good tape turns a single-pin slider into the most precise sight system on the line.

How the math works

For each target distance the calculator works out the flight time using your chronographed arrow speed (with a small drag correction), then computes the gravity drop from d = ½ × g × t². That drop is converted to a sight movement in millimeters based on the geometry between your peep, sight pin, and target.

The tape is non-linear: the gap between the 20-yard mark and the 30-yard mark is much smaller than the gap between 60 and 70. Drop grows with the square of flight time, which is why you cannot just space the marks evenly along a slider.

Verifying against real shots

A printed tape is a starting point, not a finished tool. After you generate one, shoot a known-distance target at three or four points across your range, usually 20, 40, and 60 yards. If you are hitting an inch low at 60, slide the tape down a hair and re-tape. Most field archers go through two or three iterations before a tape is fully dialed.

Common gotchas

• Heavy hunting arrows produce a different tape than light target arrows, even on the same bow
• Switching points or fletching changes drag and bumps the tape a few millimeters
• Cold morning air is denser and slows arrows slightly, so winter tournament tapes drift hot from a summer tape
• Re-chrono whenever you change a setup component, restring the bow, or notice the tape has gone stale

A tape from this calculator should land within ½ inch at 60 yards on the first shoot. If you are wider than that, double-check the chrono number and the zero distance you entered.