Tolerance & Fit Calculator

Look up ISO tolerance grades (IT01–IT18) and calculate fit clearances for common hole-shaft combinations (H7/g6, H7/k6, H7/p6). Free online engineering reference

Size Range

IT Grade

Tolerance Value (18-30 mm, IT7)

21 μm

= 0.0210 mm

All Grades for Selected Range

Grade	μm	mm
IT01	0.6	0.0006
IT0	1	0.0010
IT1	1.5	0.0015
IT2	2.5	0.0025
IT3	4	0.0040
IT4	6	0.0060
IT5	9	0.0090
IT6	13	0.0130
IT7	21	0.0210
IT8	33	0.0330
IT9	52	0.0520
IT10	84	0.0840
IT11	130	0.1300
IT12	210	0.2100
IT13	330	0.3300
IT14	520	0.5200
IT15	840	0.8400
IT16	1300	1.3000
IT17	2100	2.1000
IT18	3300	3.3000