Model Rocket Fin Size Calculator: Design for Optimal Stability

Calculate Recommended Fin Dimensions

The diameter of your rocket's body tube.
Total length of the rocket from nose tip to aft end.
Commonly 3 or 4 fins are used.
Choose a stability level (affects fin dimensions).
Select the unit for inputs and results.

Ensure your model rocket achieves stable and predictable flight with our Model Rocket Fin Size Calculator. Accurately determine the optimal fin dimensions needed for perfect aerodynamic stability, preventing crashes and guaranteeing a successful launch. Design your rocket with confidence, whether you're a hobbyist or an enthusiast!

Formula:

This calculator provides recommended fin dimensions (Root Chord, Tip Chord, Fin Height) and total fin area based on your rocket's body diameter, overall length, number of fins, and desired stability preference. The dimensions are derived using empirical factors to ensure good aerodynamic performance.

  • D = Rocket Body Diameter
  • L = Overall Rocket Length
  • N = Number of Fins
  • CR = Recommended Fin Root Chord
  • CT = Recommended Fin Tip Chord
  • H = Recommended Fin Height/Span
  • A_total = Total Surface Area of all Fins

Individual Fin Area: A_fin = ((CR + CT) / 2) × H

Total Fin Area: A_total = N × A_fin

Note: Empirical constants (k_CR, k_CT, k_H) vary based on stability preference to derive CR, CT, H from D and L.

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