Front of Center (FOC) describes how much of an arrow’s total weight is positioned toward the front of the shaft. It helps explain how an arrow is balanced and how component choices influence overall arrow flight.
This calculator estimates FOC by determining the arrow’s balance point based on the weight and location of each component, including the shaft, insert, point, vanes, nock, and any additional components.
Formula:
FOC % = ((Balance Point − (Arrow Length ÷ 2)) ÷ Arrow Length) × 100
A higher FOC means more weight is positioned toward the front of the arrow, while a lower FOC means the weight is distributed closer to the center or rear of the arrow.
Understanding FOC Values
There is no single “perfect” FOC percentage for every arrow setup. The ideal balance depends on your arrow weight, bow setup, intended use, and personal tuning preferences.
7–15% — Common FOC Range
This range is commonly seen in many hunting and target arrow builds. It provides a balanced arrow profile that can offer good stability, consistent flight, and versatility across a wide variety of setups.
15–20% — Higher FOC Range
Moving into this range places more weight toward the front of the arrow. Many hunters choose higher FOC builds to increase front-end stability and create a more forward-balanced arrow, especially when building heavier hunting arrows.
However, increasing FOC also changes an arrow’s flight characteristics. Because more weight is positioned toward the front, some archers may notice a slightly slower trajectory or increased arrow drop at longer distances. Higher FOC setups may also require additional attention to arrow spine, tuning, and component selection to maintain consistent flight.
Remember, FOC is only one part of a successful arrow setup. Arrow spine, total arrow weight, component selection, bow setup, and proper tuning all work together to determine overall arrow performance.
