Archery FOC Calculator

Calculate the Front of Center (FOC) percentage to optimize arrow flight stability and penetration potential.

Arrow Specifications

Arrow LengthThroat of nock to end of shaft (insert).

Balance PointNock throat to the arrow's balancing point.

Higher FOC (15%+) acts like a weighted dart, pulling the arrow straight and increasing penetration.

Balance Analysis

Front of Center0.00%Low FOC (Speed)

Range Comparison

Bars show upper limit of recommended ranges.

Overview

Front of Center (FOC) describes the percentage of the arrow's total weight that is located in the front half of the arrow. More weight in the front makes the arrow more stable in flight.

💡

Pro Tips

Increase FOC by using heavier points (broadheads) or lighter vanes and nocks.
Target archers often prefer a flatter trajectory with 7-11% FOC.
Hunting archers typically aim for 12-19% FOC for better penetration and stability with broadheads.
Extreme FOC (20%+) is often used by traditional archers for maximum lethality on large game.

Fun Facts

"The F.O.C. formula was popularized by Dr. Ed Ashby's research on arrow lethality."
"A low FOC arrow is more likely to be deflected by wind or brush."
"Perfectly balanced arrows (0% FOC) are extremely unstable in flight."

Used with this

Similar tools that might be useful

ACFT Score Calculator

Estimate your Army Combat Fitness Test score. Minimum 60 points per event required.

Age Graded Running

Calculate your age-graded performance percentage and equivalent 'prime' time based on WMA standards.

Anaerobic Threshold (FTP/LTHR)

Estimate your training zones based on Functional Threshold Power (FTP) or Lactate Threshold Heart Rate (LTHR).