Compound Bow FPS Calculator

Compound Bow FPS Formula:

\[ FPS_{comp\_b} = \frac{(Draw\_w_{comp} \times Draw\_l_{comp} \times 0.85)}{Arrow\_w_{comp}} \times Const_{comp} \]

Draw Weight (Draw_w_comp):

pounds

Draw Length (Draw_l_comp):

inches

Arrow Weight (Arrow_w_comp):

grains

Conversion Factor (Const_comp):

unitless

Estimated FPS (FPS_comp_b):

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1. What is the Compound Bow FPS Formula?

The Compound Bow FPS formula calculates the feet per second (FPS) velocity of an arrow shot from a compound bow. It considers draw weight, draw length, arrow weight, and a conversion factor to estimate arrow speed.

2. How Does the Calculator Work?

The calculator uses the Compound Bow FPS formula:

\[ FPS_{comp\_b} = \frac{(Draw\_w_{comp} \times Draw\_l_{comp} \times 0.85)}{Arrow\_w_{comp}} \times Const_{comp} \]

Where:

\( Draw\_w_{comp} \) — Draw weight (pounds)
\( Draw\_l_{comp} \) — Draw length (inches)
\( Arrow\_w_{comp} \) — Arrow weight (grains)
\( Const_{comp} \) — Conversion factor (unitless)
0.85 — Efficiency factor for compound bows

Explanation: The formula accounts for the energy stored in the bow (draw weight × draw length), bow efficiency (0.85), and how that energy transfers to arrow velocity based on arrow weight and conversion factor.

3. Importance of FPS Calculation

Details: Accurate FPS estimation is crucial for archers to understand arrow performance, trajectory, kinetic energy, and overall bow setup efficiency for different shooting applications.

4. Using the Calculator

Tips: Enter draw weight in pounds, draw length in inches, arrow weight in grains, and appropriate conversion factor. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical conversion factor value?
A: The conversion factor typically ranges from 0.9 to 1.1 depending on bow efficiency, cam design, and other factors.

Q2: Why is there a 0.85 efficiency factor?
A: The 0.85 factor accounts for energy loss due to friction, string stretch, and other inefficiencies in compound bow systems.

Q3: How accurate is this formula?
A: This provides a good estimate but actual FPS may vary based on specific bow characteristics, arrow spine, and shooting conditions.

Q4: What arrow weight should I use?
A: Use the total arrow weight including point, insert, shaft, fletching, and nock for most accurate results.

Q5: Can this formula be used for recurve bows?
A: No, this formula is specifically designed for compound bows. Recurve bows have different efficiency factors and calculation methods.