1. What is Arrow FOC?

Front of Center (FOC) is a measurement that describes the balance point of an arrow relative to its total length. It's expressed as a percentage and affects arrow flight stability and accuracy.

2. How Does the Calculator Work?

The calculator uses the standard FOC formula:

Where:

• Balance Point Distance — Measured from throat of nock to balance point (inches)
• Total Arrow Length — Full length of the arrow (inches)
• 9 — Standard adjustment factor (inches)

Explanation: The formula calculates what percentage of the arrow's length is in front of the center point.

3. Importance of FOC Calculation

Details: Proper FOC affects arrow stability, accuracy, and penetration. Most target arrows have 7-15% FOC, while hunting arrows typically have 10-20%.

4. Using the Calculator

Tips: Measure balance point by balancing arrow on a narrow edge. Enter both measurements in inches for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: Why subtract 9 inches in the formula?
A: This accounts for the standard AMO draw length measurement method where the arrow is 1.75" past the pivot point on a 28" draw.

Q2: What's the ideal FOC for hunting arrows?
A: Most hunters prefer 10-15% FOC for optimal balance of speed and penetration.

Q3: Does FOC affect arrow speed?
A: Higher FOC generally means slightly slower arrow speed but better stability and penetration.

Q4: How does FOC affect broadhead flight?
A: Higher FOC helps stabilize broadheads and improves accuracy, especially with fixed-blade heads.

Q5: Can FOC be too high?
A: Yes, excessive FOC (>20%) can make arrows unstable in flight and reduce speed significantly.