1. What is Arrow FOC?

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

2. How Does the Calculator Work?

The calculator uses the FOC formula:

Where:

• \( L \) — Total arrow length (inches)
• \( AMO \) — Arrow mass offset (distance from rear end to balance point in inches)

The weight calculation simply sums all component weights entered (shaft, point, fletching, etc.).

3. Importance of FOC and Weight

Details: Proper FOC (typically 10-15% for most setups) improves arrow flight and accuracy. Total weight affects speed, kinetic energy, and penetration.

4. Using the Calculator

Tips: Measure arrow length from nock groove to end of shaft. For AMO, find balance point and measure from nock end. Enter all component weights in grains separated by commas.

5. Frequently Asked Questions (FAQ)

Q1: What's the ideal FOC percentage?
A: Most target arrows perform well at 10-15%. Hunting arrows often benefit from 12-20% for better penetration.

Q2: How does arrow weight affect performance?
A: Heavier arrows have more kinetic energy and penetration but fly slower. Lighter arrows are faster but may lack stability in wind.

Q3: Should I include insert weight?
A: Yes, include all components that affect the arrow's total mass and balance point.

Q4: How do I measure AMO accurately?
A: Balance the complete arrow on a narrow edge and measure from nock end to balance point.

Q5: Does FOC affect broadhead flight?
A: Yes, higher FOC often improves broadhead stability and accuracy, especially with fixed-blade heads.