1. What is Arrow FOC?

Front of Center (FOC) is a measurement that describes how much of an arrow's total weight is located in the front half of the arrow. It's expressed as a percentage and affects arrow flight stability and accuracy.

2. How Does the Calculator Work?

The calculator uses the Easton FOC formula:

Where:

• \( balance \) — Balance point measured from nock end (inches)
• \( L \) — Total arrow length (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 is crucial for optimal arrow flight. Higher FOC (10-15%) increases stability for long-distance shots, while lower FOC (7-10%) may be better for short-range hunting.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is a good FOC percentage?
A: Most target arrows perform well at 10-15% FOC. Hunting arrows often use 10-12%. Experiment to find what works best for your setup.

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 or at long distances.

Q3: How do I adjust FOC?
A: Add weight to point (increases FOC) or use heavier nocks/rear components (decreases FOC). Arrow length changes also affect FOC.

Q4: Does FOC matter for compound bows?
A: Yes, though the effect may be less noticeable than with traditional bows due to higher arrow speeds.

Q5: Is Easton FOC the only calculation method?
A: No, some archers use different formulas, but Easton's is the most widely accepted standard.