Air hole calculator for model rocket altimeters

Calculate the correct vent hole size for your rocket body tube.

Dimensions

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Minimum distance from transitions: 225 mm
Holes should be placed at least 3× the tube OD from any nosecone, shoulder or body tube transition to ensure accurate static pressure readings during flight.

For thick-walled tubes (3mm+), consider drilling slightly larger holes to compensate for reduced airflow through the tube wall.

hole_dia = 0.004396 × tube_dia × √(tube_length / num_holes)