Motor Size Classes

This information was provided by the Tripoli Rocketry Association, Inc. Please visit their web site at: www.tripoli.org.

Rocket motors are classed by time and pressure. Each successive letter is doubled. In other words a "B" motor has double the power of an "A" motor and so on. NAR and Tripoli are limited up to an "O" motor. Anything bigger or more powerful requires special permission to fly by the governing authorities.

Impulse Class	Min. Newton's	Max. Newton's	Min. Pounds	Max. Pounds
A	1.25	2.5	.28	.55
B	2.51	5	.55	1.10
C	5.01	10	1.10	2.2
D	10.01	20	2.2	4.41
E	20.01	40	4.41	8.81
F	40.01	80	8.81	17.62
G	80.01	160	17.62	35.24
H	160.01	320	35.24	70.48
I	320.01	640	70.48	140.97
J	640.01	1280	140.97	281.94
K	1280.01	2560	281.94	563.88
L	2560.01	5120	563.88	1127.75
M	5120.01	10240	1127.75	2255.51
N	10240.01	20480	2255.51	4511.01
O	20480.01	40960	4511.01	9022.03
P	40960.01	81920	9022.03	18044.05
Q	81920.01	163840	18044.05	36088.11
R	163840.01	327680	36088.11	72176.21
S	327680.01	655360	72176.21	144352.42
T	655360.01	1310720	144352.42	288704.85
U	1310720.01	2621440	288704.85	577409.69
V	2621440.01	5242880	577409.69	1154819.38
W	5242880.01	10485760	1154819.38	2309638.77
X	10485760.01	20971520	2309638.77	4619277.53