1. What Is Arrow FOC?

FOC (Front of Center) is a measurement that describes the balance point of an arrow relative to its length. It's expressed as a percentage that indicates how much of the arrow's weight is in the front half of the arrow.

2. How Does the Calculator Work?

The calculator uses the FOC equation:

Where:

• \( FOC \) — Front of Center percentage
• \( L \) — Total arrow length (inches)
• \( AMO \) — Balance point measurement from nock end (inches)

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

3. Importance of FOC Calculation

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

4. Using the Calculator

Tips: Measure arrow length from nock groove to end of shaft (not including point). Measure balance point by finding where the arrow balances on a narrow edge.

5. Frequently Asked Questions (FAQ)

Q1: What is a good FOC percentage?
A: For target shooting, 7-15% is typical. For hunting, 10-20% provides better penetration. Extreme FOC (>25%) may require specialized setups.

Q2: How does FOC affect arrow flight?
A: Higher FOC makes arrows more stable but slower. Lower FOC makes arrows faster but less stable in wind.

Q3: How can I adjust my arrow's FOC?
A: Add weight to front (heavier points, inserts) to increase FOC. Add weight to rear (weight tubes, heavier nocks) to decrease FOC.

Q4: Does FOC matter for compound bows?
A: Yes, though modern compounds are more forgiving. Traditional bows (recurve, longbow) are more sensitive to FOC variations.

Q5: Should I include vanes/fletching in measurements?
A: No, measure only the shaft length and balance point without fletching for most accurate FOC calculation.