Drill Bit Size Chart

Drill can be defined as a rotary end cutting tool which having one or more cutting lips and having one or more helical flutes for passage of chips and admission of a cutting fluid.

Drill bits are cutting tools used in drilling to create cylindrical cross-section holes. Drill bits are comes in various sizes for various types of applications.

The drill bit size chart provides a list of standard sizes of drill bits in several measurement systems including fractional and metric sizes.

The drill bit shown in figure as per ANSI/ASME and ISO standards. The Frictional sizes are measured in inches and the Metric sizes are measured in millimeters.

ANSI Size Drill Bit Chart:

Drill (in.)	Decimal	Drill (in.)	Decimal	Drill (in.)	Decimal
80	0.0135	1/8	0.1250	0	0.3160
79	0.0145	30	0.1285	p	0.3230
1/64	0.0156	29	0.1360	21/64	0.3281
78	0.0160	28	0.1405	Q	0.3320
77	0.0180	9/64	0.1406	R	0.3390
76	0.0200	27	0.1440	11/32	0.3437
75	0.0210	26	0.1470	s	0.3480
74	0.0225	25	0.1495	T	0.3580
73	0.0240	24	0.1520	23/64	0.3594
72	0.0250	23	0.1540	u	0.3680
71	0.0260	5/32	0.1562	3/8	0.3750
70	0.0280	22	0.1570	V	0.3770
69	0.0292	21	0.1590	W	0.3860
68	0.0310	20	0.1610	25/64	0.3906
1/32	0.0313	19	0.1660	X	0.3970
67	0.0320	18	0.1695	Y	0.4040
66	0.0330	11/64	0.1719	13/32	0.4062
65	0.0350	17	0.1730	Z	0.4130
64	0.0360	16	0.1770	27/64	0.4219
63	0.0370	15	0.1800	7/16	0.4375
62	0.0380	14	0.1820	29/64	0.4531
61	0.0390	13	0.1850	15/32	0.4687
60	0.0400	3/16	0.1875	31/64	0.4844
59	0.0410	12	0.1890	1/2	0.5000
58	0.0420	11	0.1910	33/64	0.5156
57	0.0430	10	0.1935	17/32	0.5312
56	0.0465	9	0.1960	35/64	0.5469
3/64	0.0469	8	0.1990	9/16	0.5625
55	0.0520	7	0.2010	37/64	0.5781
54	0.0550	13/64	0.2031	19/32	0.5937
53	0.0595	6	0.2040	39/64	0.6094
1/16	0.0625	5	0.2055	5/8	0.6250
52	0.0635	4	0.2090	41/64	0.6406
51	0.0670	3	0.2130	21/32	0.6562
50	0.0700	7/32	0.2187	43/64	0.6719
49	0.0730	2	0.2210	11/16	0.6875
48	0.0760	1	0.2280	45/64	0.7031
5/64	0.0781	A	0.2340	23/32	0.7187
47	0.0785	15/64	0.2344	47/64	0.7344
46	0.0810	B	0.2380	3/4	0.7500
45	0.0820	C	0.2420	49/64	0.7656
44	0.0860	D	0.2460	25/32	0.7812
43	0.0890	E	0.2500	51/64	0.7969
42	0.0935	1/4	0.2500	13/16	0.8125
3/32	0.0937	F	0.2570	53/64	0.8281
41	0.0960	G	0.2610	27/32	0.8437
40	0.0980	17/64	0.2656	55/64	0.8594
39	0.0995	H	0.2660	7/8	0.8750
38	0.1015	I	0.2720	57/64	0.8906
37	0.1040	J	0.2770	29/32	0.9062
36	0.1065	K	0.2811	59/64	0.9219
7/64	0.1093	9/32	0.2812	15/16	0.9375
35	0.1100	L	0.2900	61/64	0.9531
34	0.1110	M	0.2950	31/32	0.9687
33	0.1130	19/64	0.2968	63/64	0.9844
32	0.1160	N	0.3020	1	1.0000
31	0.1200	5/16	0.3125

ISO (Metric Size Drills) and Conversion to Inches Chart:

Drill (mm)	Decimal (in.)	Drill (mm)	Decimal (in.)	Drill (mm)	Decimal (in.)
0.35	0.0138	3.4	0.1339	8.0	0.3150
0.4	0.0157	3.5	0.1378	8.1	0.3189
0.45	0.0177	3.6	0.1417	8.2	0.3228
0.5	0.0197	3.7	0.1457	8.3	0.3248
0.55	0.0217	3.75	0.1477	8.3	0.3267
0.6	0.0236	3.8	0.1496	8.4	0.3307
0.65	0.0256	3.9	0.1535	8.5	0.3346
0.7	0.0276	4	0.1575	8.6	0.3386
0.75	0.0295	4.1	0.1614	0.1614	0.3425
0.8	0.0315	4.2	0.1654	8.8	0.3445
0.85	0.0335	4.25	0.1674	8.8	0.3465
0.9	0.0355	4.3	0.1693	8.9	0.3504
0.95	0.0374	4.4	0.1732	9.0	0.3543
1	0.0394	4.5	0.1771	9.1	0.3583
1.05	0.0413	4.6	0.1811	9.2	0.3622
1.10	0.0433	4.7	0.1850	9.3	0.3642
1.15	0.0453	4.75	0.1870	9.4	0.3661
1.2	0.0472	4.8	0.1890	9.4	0.3701
1.25	0.0492	4.9	0.1929	9.5	0.3740
1.3	0.0512	5	0.1968	9.6	0.3780
1.35	0.0531	5.1	0.2008	9.7	0.3819
1.4	0.0551	5.2	0.2047	9.8	0.3839
1.45	0.0571	5.25	0.2067	9.8	0.3858
1.5	0.0591	5.3	0.2087	9.9	0.3898
1.55	0.0610	5.4	0.2126	10.0	0.3937
1.60	0.0629	5.5	0.2165	10.5	0.4133
1.65	0.0650	5.6	0.2205	11.0	0.4331
1.7	0.0669	5.7	0.2244	11.5	0.4528
1.75	0.0689	5.75	0.2264	12.0	0.4724
1.8	0.0709	5.8	0.2283	12.5	0.4921
1.85	0.0728	5.9	0.2323	13.0	0.5118
1.9	0.0748	6	0.2362	13.5	0.5315
1.95	0.0768	6.1	0.2401	14.0	0.5512
2	0.0787	6.2	0.2441	14.5	0.5708
2.05	0.0807	6.25	0.2461	15.0	0.5906
2.1	0.0827	6.3	0.2480	15.5	0.6102
2.15	0.0846	6.4	0.2520	16.0	0.6300
2.2	0.0866	6.5	0.2559	16.5	0.6496
2.25	0.0886	6.6	0.2598	17.0	0.6693
2.3	0.0905	6.7	0.2638	17.5	0.6889
2.35	0.0925	6.75	0.2658	18.0	0.7087
2.4	0.0945	6.8	0.2677	18.5	0.7283
2.45	0.0965	6.9	0.2716	19.0	0.7480
2.5	0.0984	7	0.2756	19.5	0.7677
2.55	0.1004	7.1	0.2795	20.0	0.7874
2.6	0.1024	7.2	0.2835	20.5	0.8071
2.65	0.1043	7.25	0.2855	21.0	0.8268
2.7	0.1063	7.3	0.2874	21.5	0.8465
2.75	0.1083	7.4	0.2913	22.0	0.8661
2.8	0.1102	7.5	0.2953	22.5	0.8858
2.9	0.1142	7.6	0.2990	23.0	0.9055
3	0.1181	7.7	0.3031	23.5	0.9252
3.1	0.1220	7.75	0.3051	24.0	0.9449
3.2	0.1260	7.8	0.3071	24.5	0.9646
3.25	0.1280	7.9	0.3110	25.0	0.9843
3.3	0.1299

Fractional and Metric Sizes as per ANSI/ASME B94.11M-1993