Spherical Parachute Patterns

This web page will produce patterns for hemisphere parachutes for model rockets. Instructions for constructing the parachutes can be found in the May/June 2000 newsletter of the Northern Illinois Rocketry Association.

The article describes the construction of 12 inch diameter parachute with 8 gores and a 2 inch diameter spill hole. This web page will produce patterns for other sizes of parachutes.

As you are considering the size of your parachute, keep in mind that a spherical parachute has twice the drag coefficient of a comparable sized parasheet style parachute that comes with most model rocket kits.

Parachute shroud lines should be 1 1/2 times the diameter of the parachute.

Please check your print settings before printing the pattern. Acrobat Reader should be set to print Actual Size.

Larger parachure patterns may print over several pages.

So what size parachute do you need? Let's find out.

Weight of payload in ounces:    

Create a Parachute Pattern

Parachute Dimension Units



Parachute Diameter

Percent of Sphere

50% will produce a hemisphere parachute. 25% will produce a half-hemisphere parachute. 100% will produce a full sphere. Percents below 25 may give unexpected results.

Number of Gores

Spill Hole Diameter

Seam Allowance

The seam alowance will be drawn on both sides of each gore, but not at the top or bottom










Paper Size





     x    (at least 8 x 8 in (21cm x 21cm), not more than 120 x 120 in (300cm x 300cm)

Paper Orientation