Enter your bow length and select the type of bow to get a recommended brace height range. For compound bows, “bow length” is typically axle-to-axle (ATA). For recurves and longbows, use the AMO bow length (overall bow length). The brace height is the distance from the deepest part of the bow’s grip (pivot point) to the string when the bow is strung.
Brace Height Formula
There is no universal formula that calculates brace height from bow length. Brace height is primarily a manufacturer/design specification (especially for compound bows) and a tuning setting within a recommended range for recurves and longbows (adjusted mainly by string length and twist count).
A practical way to “calculate” a good starting brace height is to use the manufacturer’s recommended range. If you don’t have a manual, common starting ranges (in inches) by bow length are:
- Recurve (AMO 58–72″): approximately 7.5–10.0″ depending on bow length and limb design (see the “Recommended Range” tab for typical starting ranges by AMO length).
- Longbow (AMO 60–72″): approximately 7.0–8.25″ depending on design (straight longbow vs hybrid).
- Compound: follow your bow’s tune chart/manual; typical values are roughly 5.0–8.0″ depending on model.
Variables (typical units):
- BH is the brace height (inches)
- Bow length is ATA for compound bows (inches) and AMO bow length for recurves/longbows (inches)
For the most accurate results, use the brace height range printed by the manufacturer and tune within that range.
What is Brace Height?
Brace height is the distance from the deepest part of the bow’s grip (pivot point) to the string when the bow is strung. It is an important measurement for archers as it affects the performance and feel of the bow. A proper brace height can improve accuracy, reduce vibration, and increase comfort during shooting.
How to Calculate Brace Height?
The following steps outline how to determine and set the Brace Height.
- Identify your bow type (recurve, longbow, or compound).
- Determine the appropriate length measurement: for compound bows, use axle-to-axle (ATA); for recurves/longbows, use the AMO bow length (overall length) marked on the bow or provided by the manufacturer.
- Find the manufacturer’s recommended brace height (or a recommended starting range for your AMO length).
- Measure your current brace height with a bow square (from the pivot point of the grip to the string).
- If using a recurve/longbow, adjust brace height mainly by adding/removing twists in the string (within the safe/allowed range for your string and bow). For compound bows, do not “tune by guess”—use the tune chart/manual and make adjustments only as recommended by the manufacturer.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Bow Length (AMO) = 68 inches
Bow Type = Recurve
A typical starting brace height range for a 68″ recurve is approximately 8.75–9.50 inches. A common starting point is the midpoint of the range:
BH ≈ (8.75 + 9.50) / 2 = 9.125 inches (start here, then fine-tune within the recommended range)
