Drill Size Chart

The drill size chart provides a list of standard size drill bits in several measurement systems, including fractional, metric, wire gauge number, and letter. The decimal equivalents of the diameters are shown in both English and Metric units. Fractional sizes are measured in inches, while metric sizes are measured in millimeters. The wire gauge and letter systems refer to tool diameters that increase as the wire gauge decreases from #107 to #1 and then continues from A to Z. The drill size chart contains tools up to 1.5 inches in diameter, but larger tools are also commonly used.

Drill size	Diameter (in)	Diameter (mm)
#107	0.0019	0.0483
0.05 mm	0.0020	0.0500
#106	0.0023	0.0584
#105	0.0027	0.0686
#104	0.0031	0.0787
#103	0.0035	0.0889
#102	0.0039	0.0991
0.1 mm	0.0039	0.1000
#101	0.0043	0.1092
#100	0.0047	0.1194
#99	0.0051	0.1295
#98	0.0055	0.1397
#97	0.0059	0.1499
#96	0.0063	0.1600
#95	0.0067	0.1702
#94	0.0071	0.1803
#93	0.0075	0.1905
0.2 mm	0.0079	0.2000
#92	0.0079	0.2007
#91	0.0083	0.2108
#90	0.0087	0.2210
#89	0.0091	0.2311
#88	0.0095	0.2413
#87	0.0100	0.2540
#86	0.0105	0.2667
#85	0.0110	0.2794
#84	0.0115	0.2921
0.3 mm	0.0118	0.3000
#83	0.0120	0.3048
#82	0.0125	0.3175
#81	0.0130	0.3302
#80	0.0135	0.3429
#79	0.0145	0.3680
1/64 in	0.0156	0.3969
0.4 mm	0.0158	0.4000
#78	0.0160	0.4064
#77	0.0180	0.4572
0.5 mm	0.0197	0.5000
#76	0.0200	0.5080
#75	0.0210	0.5334
#74	0.0225	0.5715
0.6 mm	0.0236	0.6000
#73	0.0240	0.6096
#72	0.0250	0.6350
#71	0.0260	0.6604
0.7 mm	0.0276	0.7000
#70	0.0280	0.7112
#69	0.0292	0.7417
#68	0.0310	0.7874
1/32 in	0.0313	0.7938
0.8 mm	0.0315	0.8000
#67	0.0320	0.8128
#66	0.0330	0.8382
#65	0.0350	0.8890
0.9 mm	0.0354	0.9000
#64	0.0360	0.9144
#63	0.0370	0.9398
#62	0.0380	0.9652
#61	0.0390	0.9906
1 mm	0.0394	1.0000
#60	0.0400	1.0160
#59	0.0410	1.0414
#58	0.0420	1.0668
#57	0.0430	1.0922
1.1 mm	0.0433	1.1000
#56	0.0465	1.1811
3/64 in	0.0469	1.1906
1.2 mm	0.0472	1.2000
1.3 mm	0.0512	1.3000
#55	0.0520	1.3208
#54	0.0550	1.3970
1.4 mm	0.0551	1.4000
1.5 mm	0.0591	1.5000
#53	0.0595	1.5113
1/16 in	0.0625	1.5875
1.6 mm	0.0630	1.6000
#52	0.0635	1.6129
1.7 mm	0.0669	1.7000
#51	0.0670	1.7018
#50	0.0700	1.7780
1.8 mm	0.0709	1.8000
#49	0.0730	1.8542
1.9 mm	0.0748	1.9000
#48	0.0760	1.9304
5/64 in	0.0781	1.9844
#47	0.0785	1.9939
2 mm	0.0787	2.0000
#46	0.0810	2.0574
#45	0.0820	2.0828
2.1 mm	0.0827	2.1000
#44	0.0860	2.1844
2.2 mm	0.0866	2.2000
#43	0.0890	2.2606
2.3 mm	0.0906	2.3000
#42	0.0935	2.3749
3/32 in	0.0938	2.3813
2.4 mm	0.0945	2.4000
#41	0.0960	2.4384
#40	0.0980	2.4892
2.5 mm	0.0984	2.5000
#39	0.0995	2.5273
#38	0.1015	2.5781
2.6 mm	0.1024	2.6000
#37	0.1040	2.6416
2.7 mm	0.1063	2.7000
#36	0.1065	2.7051
7/64 in	0.1094	2.7781
#35	0.1100	2.7940
2.8 mm	0.1102	2.8000
#34	0.1110	2.8194
#33	0.1130	2.8702
2.9 mm	0.1142	2.9000
#32	0.1160	2.9464
3 mm	0.1181	3.0000
#31	0.1200	3.0480
3.1 mm	0.1221	3.1000
1/8 in	0.1250	3.1750
3.2 mm	0.1260	3.2000
#30	0.1285	3.2639
3.3 mm	0.1299	3.3000
3.4 mm	0.1339	3.4000
#29	0.1360	3.4544
3.5 mm	0.1378	3.5000
#28	0.1405	3.5687
9/64 in	0.1406	3.5719
3.6 mm	0.1417	3.6000
#27	0.1440	3.6576
3.7 mm	0.1457	3.7000
#26	0.1470	3.7338
#25	0.1495	3.7973
3.8 mm	0.1496	3.8000
#24	0.1520	3.8608
3.9 mm	0.1535	3.9000
#23	0.1540	3.9116
5/32 in	0.1563	3.9688
#22	0.1570	3.9878
4 mm	0.1575	4.0000
#21	0.1590	4.0386
#20	0.1610	4.0894
4.1 mm	0.1614	4.1000
4.2 mm	0.1654	4.2000
#19	0.1660	4.2164
4.3 mm	0.1693	4.3000
#18	0.1695	4.3053
11/64 in	0.1719	4.3656
#17	0.1730	4.3942
4.4 mm	0.1732	4.4000
#16	0.1770	4.4958
4.5 mm	0.1772	4.5000
#15	0.1800	4.5720
4.6 mm	0.1811	4.6000
#14	0.1820	4.6228
#13	0.1850	4.6990
4.7 mm	0.1850	4.7000
3/16 in	0.1875	4.7625
4.8 mm	0.1890	4.8000
#12	0.1890	4.8006
#11	0.1910	4.8514
4.9 mm	0.1929	4.9000
#10	0.1935	4.9149
#9	0.1960	4.9784
5 mm	0.1969	5.0000
#8	0.1990	5.0546
5.1 mm	0.2008	5.1000
#7	0.2010	5.1054
13/64 in	0.2031	5.1594
#6	0.2040	5.1816
5.2 mm	0.2047	5.2000
#5	0.2055	5.2197
5.3 mm	0.2087	5.3000
#4	0.2090	5.3086
5.4 mm	0.2126	5.4000
#3	0.2130	5.4102
5.5 mm	0.2165	5.5000
7/32 in	0.2188	5.5563
5.6 mm	0.2205	5.6000
#2	0.2210	5.6134
5.7 mm	0.2244	5.7000
#1	0.2280	5.7912
5.8 mm	0.2284	5.8000
5.9 mm	0.2323	5.9000
A	0.2340	5.9436
15/64 in	0.2344	5.9531
6 mm	0.2362	6.0000
B	0.2380	6.0452
6.1 mm	0.2402	6.1000
C	0.2420	6.1468
6.2 mm	0.2441	6.2000
D	0.2460	6.2484
6.3 mm	0.2480	6.3000
1/4 in	0.2500	6.3500
E	0.2500	6.3500
6.4 mm	0.2520	6.4000
6.5 mm	0.2559	6.5000
F	0.2570	6.5278
6.6 mm	0.2598	6.6000
G	0.2610	6.6294
6.7 mm	0.2638	6.7000
17/64 in	0.2656	6.7469
H	0.2660	6.7564
6.8 mm	0.2677	6.8000
6.9 mm	0.2717	6.9000
I	0.2720	6.9088
7 mm	0.2756	7.0000
J	0.2770	7.0358
7.1 mm	0.2795	7.1000
K	0.2810	7.1374
9/32 in	0.2813	7.1438
7.2 mm	0.2835	7.2000
7.3 mm	0.2874	7.3000
L	0.2900	7.3660
7.4 mm	0.2913	7.4000
M	0.2950	7.4930
7.5 mm	0.2953	7.5000
19/64 in	0.2969	7.5406
7.6 mm	0.2992	7.6000
N	0.3020	7.6708
7.7 mm	0.3032	7.7000
7.8 mm	0.3071	7.8000
7.9 mm	0.3110	7.9000
5/16 in	0.3125	7.9375
8 mm	0.3150	8.0000
O	0.3160	8.0264
8.1 mm	0.3189	8.1000
8.2 mm	0.3228	8.2000
P	0.3230	8.2042
8.3 mm	0.3268	8.3000
21/64 in	0.3281	8.3344
8.4 mm	0.3307	8.4000
Q	0.3320	8.4328
8.5 mm	0.3347	8.5000
8.6 mm	0.3386	8.6000
R	0.3390	8.6106
8.7 mm	0.3425	8.7000
11/32 in	0.3438	8.7313
8.8 mm	0.3465	8.8000
S	0.3480	8.8392
8.9 mm	0.3504	8.9000
9 mm	0.3543	9.0000
T	0.3580	9.0932
9.1 mm	0.3583	9.1000
23/64 in	0.3594	9.1281
9.2 mm	0.3622	9.2000
9.3 mm	0.3661	9.3000
U	0.3680	9.3472
9.4 mm	0.3701	9.4000
9.5 mm	0.3740	9.5000
3/8 in	0.3750	9.5250
V	0.3770	9.5758
9.6 mm	0.3780	9.6000
9.7 mm	0.3819	9.7000
9.8 mm	0.3858	9.8000
W	0.3860	9.8044
9.9 mm	0.3898	9.9000
25/64 in	0.3906	9.9219
10 mm	0.3937	10.0000
X	0.3970	10.0838
Y	0.4040	10.2616
13/32 in	0.4063	10.3188
Z	0.4130	10.4902
10.5 mm	0.4134	10.5000
27/64 in	0.4219	10.7156
11 mm	0.4331	11.0000
7/16 in	0.4375	11.1125
11.5 mm	0.4528	11.5000
29/64 in	0.4531	11.5094
15/32 in	0.4688	11.9063
12 mm	0.4724	12.0000
31/64 in	0.4844	12.3031
12.5 mm	0.4921	12.5000
1/2 in	0.5000	12.7000
13 mm	0.5118	13.0000
33/64 in	0.5156	13.0969
17/32 in	0.5313	13.4938
13.5 mm	0.5315	13.5000
35/64 in	0.5469	13.8906
14 mm	0.5512	14.0000
9/16 in	0.5625	14.2875
14.5 mm	0.5709	14.5000
37/64 in	0.5781	14.6844
15 mm	0.5906	15.0000
19/32 in	0.5938	15.0813
39/64 in	0.6094	15.4781
15.5 mm	0.6102	15.5000
5/8 in	0.6250	15.8750
16 mm	0.6299	16.0000
41/64 in	0.6406	16.2719
16.5 mm	0.6496	16.5000
17 mm	0.6693	17.0000
43/64 in	0.6719	17.0656
11/16 in	0.6875	17.4625
17.5 mm	0.6890	17.5000
45/64 in	0.7031	17.8594
18 mm	0.7087	18.0000
23/32 in	0.7188	18.2563
18.5 mm	0.7284	18.5000
47/64 in	0.7344	18.6531
19 mm	0.7480	19.0000
3/4 in	0.7500	19.0500
49/64 in	0.7656	19.4469
19.5 mm	0.7677	19.5000
25/32 in	0.7813	19.8438
20 mm	0.7874	20.0000
51/64 in	0.7969	20.2406
20.5 mm	0.8071	20.5000
13/16 in	0.8125	20.6375
21 mm	0.8268	21.0000
53/64 in	0.8281	21.0344
27/32 in	0.8438	21.4313
21.5 mm	0.8465	21.5000
55/64 in	0.8594	21.8281
22 mm	0.8661	22.0000
7/8 in	0.8750	22.2250
22.5 mm	0.8858	22.5000
57/64 in	0.8906	22.6219
23 mm	0.9055	23.0000
29/32 in	0.9063	23.0188
21/23 in	0.9130	23.1913
59/64 in	0.9219	23.4156
23.5 mm	0.9252	23.5000
15/16 in	0.9375	23.8125
24 mm	0.9449	24.0000
61/64 in	0.9531	24.2094
24.5 mm	0.9646	24.5000
31/32 in	0.9688	24.6063
25 mm	0.9843	25.0000
63/64 in	0.9844	25.0031
1 in	1.0000	25.4000
25.5 mm	1.0039	25.5000
1 1/64 in	1.0156	25.7969
26 mm	1.0236	26.0000
1 1/32 in	1.0313	26.1938
26.5 mm	1.0433	26.5000
1 3/64 in	1.0469	26.5906
1 1/16 in	1.0625	26.9875
27 mm	1.0630	27.0000
1 5/64 in	1.0781	27.3844
27.5 mm	1.0827	27.5000
1 3/32 in	1.0938	27.7813
28 mm	1.1024	28.0000
1 7/64 in	1.1094	28.1781
28.5 mm	1.1221	28.5000
1 1/8 in	1.1250	28.5750
1 9/64 in	1.1406	28.9719
29 mm	1.1417	29.0000
1 5/32 in	1.1563	29.3688
29.5 mm	1.1614	29.5000
1 11/64 in	1.1719	29.7656
30 mm	1.1811	30.0000
1 3/16 in	1.1875	30.1625
30.5 mm	1.2008	30.5000
1 13/64 in	1.2031	30.5594
1 7/32 in	1.2188	30.9563
31 mm	1.2205	31.0000
1 15/64 in	1.2344	31.3531
31.5 mm	1.2402	31.5000
1 1/4 in	1.2500	31.7500
32 mm	1.2598	32.0000
1 17/64 in	1.2656	32.1469
32.5 mm	1.2795	32.5000
1 9/32 in	1.2813	32.5438
1 19/64 in	1.2969	32.9406
33 mm	1.2992	33.0000
1 5/16 in	1.3125	33.3375
33.5 mm	1.3189	33.5000
1 21/64 in	1.3281	33.7344
34 mm	1.3386	34.0000
1 11/32 in	1.3438	34.1313
34.5 mm	1.3583	34.5000
1 23/64 in	1.3594	34.5281
1 3/8 in	1.3750	34.9250
35 mm	1.3780	35.0000
1 25/64 in	1.3906	35.3219
35.5 mm	1.3976	35.5000
1 13/32 in	1.4063	35.7188
36 mm	1.4173	36.0000
1 27/64 in	1.4219	36.1156
36.5 mm	1.4370	36.5000
1 7/16 in	1.4375	36.5125
1 29/64 in	1.4531	36.9094
37 mm	1.4567	37.0000
1 15/32 in	1.4688	37.3063
37.5 mm	1.4764	37.5000
1 31/64 in	1.4844	37.7031
38 mm	1.4961	38.0000
1 1/2 in	1.5000	38.1000