Noise Criterion Calculator

Sound Pressure Level (dB) – Octave band mid-frequency (Hz)

The calculator to calculate the NC – Noise Criterion.

Noise Criterion	Octave Band Center Frequency (Hz)
	63	125	250	500	1000	2000	4000	8000
	Sound Pressure Levels (dB)
NC-15	47	36	29	22	17	14	12	11
NC-20	51	40	33	26	22	19	17	16
NC-25	54	44	37	31	27	24	22	21
NC-30	57	48	41	35	31	29	28	27
NC-35	60	52	45	40	36	34	33	32
NC-40	64	56	50	45	41	39	38	37
NC-45	67	60	54	49	46	44	43	42
NC-50	71	64	58	54	51	49	48	47
NC-55	74	67	62	58	56	54	53	52
NC-60	77	71	67	63	61	59	58	57
NC-65	80	75	71	68	66	64	63	62
NC-70	83	79	75	72	71	70	69	68