Motor Starter Sizing Calculator

Size NEMA motor starters, contactors, and overload relays per NEC Article 430.

Motor Horsepower

Voltage

Phase

Service Factor

Starter Type

Duty Cycle

NEMA sizes based on horsepower and voltage ratings.

NEMA Size	200V HP	230V HP	460V HP	575V HP
00	1.5	1.5	2	2
0	3	3	5	5
1	7.5	7.5	10	10
2	10	15	25	25
3	25	30	50	50
4	40	50	100	100
5	75	100	200	200
6	150	200	400	400

Motor Overload Protection (NEC 430.32)

NEMA Size	200V HP	230V HP	460V HP	575V HP
00	1.5	1.5	2	2
0	3	3	5	5
1	7.5	7.5	10	10
2	10	15	25	25
3	25	30	50	50
4	40	50	100	100
5	75	100	200	200
6	150	200	400	400

NEMA Size	200V HP	230V HP	460V HP	575V HP
00	1.5	1.5	2	2
0	3	3	5	5
1	7.5	7.5	10	10
2	10	15	25	25
3	25	30	50	50
4	40	50	100	100
5	75	100	200	200
6	150	200	400	400

NEMA Size	200V HP	230V HP	460V HP	575V HP
00	1.5	1.5	2	2
0	3	3	5	5
1	7.5	7.5	10	10
2	10	15	25	25
3	25	30	50	50
4	40	50	100	100
5	75	100	200	200
6	150	200	400	400