Drill Bit Size Charts
This drill bit size chart provides a list of sizes in several measurement systems, including fractional, metric, wire gauge number, and letter.
Fractional Drill Bit Size Chart
Drill size  | Diameter (in)  | Diameter (mm)  | 
1/64 in  | 0.0156  | 0.3969  | 
1/32 in  | 0.0313  | 0.7938  | 
3/64 in  | 0.0469  | 1.1906  | 
0.0625  | 1.5875  | |
0.0781  | 1.9844  | |
3/32 in  | 0.0938  | 2.3813  | 
7/64 in  | 0.1094  | 2.7781  | 
1/8 in  | 0.125  | 3.175  | 
9/64 in  | 0.1406  | 3.5719  | 
5/32 in  | 0.1563  | 3.9688  | 
11/64 in  | 0.1719  | 4.3656  | 
3/16 in  | 0.1875  | 4.7625  | 
13/64 in  | 0.2031  | 5.1594  | 
7/32 in  | 0.2188  | 5.5563  | 
15/64 in  | 0.2344  | 5.9531  | 
1/4 in  | 0.25  | 6.35  | 
17/64 in  | 0.2656  | 6.7469  | 
9/32 in  | 0.2813  | 7.1438  | 
19/64 in  | 0.2969  | 7.5406  | 
5/16 in  | 0.3125  | 7.9375  | 
21/64 in  | 0.3281  | 8.3344  | 
11/32 in  | 0.3438  | 8.7313  | 
23/64 in  | 0.3594  | 9.1281  | 
3/8 in  | 0.375  | 9.525  | 
25/64 in  | 0.3906  | 9.9219  | 
13/32 in  | 0.4063  | 10.3188  | 
27/64 in  | 0.4219  | 10.7156  | 
7/16 in  | 0.4375  | 11.1125  | 
29/64 in  | 0.4531  | 11.5094  | 
15/32 in  | 0.4688  | 11.9063  | 
31/64 in  | 0.4844  | 12.3031  | 
1/2 in  | 0.5  | 12.7  | 
33/64 in  | 0.5156  | 13.0969  | 
17/32 in  | 0.5313  | 13.4938  | 
35/64 in  | 0.5469  | 13.8906  | 
9/16 in  | 0.5625  | 14.2875  | 
37/64 in  | 0.5781  | 14.6844  | 
19/32 in  | 0.5938  | 15.0813  | 
39/64 in  | 0.6094  | 15.4781  | 
5/8 in  | 0.625  | 15.875  | 
41/64 in  | 0.6406  | 16.2719  | 
43/64 in  | 0.6719  | 17.0656  | 
11/16 in  | 0.6875  | 17.4625  | 
45/64 in  | 0.7031  | 17.8594  | 
23/32 in  | 0.7188  | 18.2563  | 
47/64 in  | 0.7344  | 18.6531  | 
3/4 in  | 0.75  | 19.05  | 
49/64 in  | 0.7656  | 19.4469  | 
25/32 in  | 0.7813  | 19.8438  | 
51/64 in  | 0.7969  | 20.2406  | 
13/16 in  | 0.8125  | 20.6375  | 
53/64 in  | 0.8281  | 21.0344  | 
27/32 in  | 0.8438  | 21.4313  | 
55/64 in  | 0.8594  | 21.8281  | 
7/8 in  | 0.875  | 22.225  | 
57/64 in  | 0.8906  | 22.6219  | 
29/32 in  | 0.9063  | 23.0188  | 
21/23 in  | 0.913  | 23.1913  | 
59/64 in  | 0.9219  | 23.4156  | 
15/16 in  | 0.9375  | 23.8125  | 
61/64 in  | 0.9531  | 24.2094  | 
31/32 in  | 0.9688  | 24.6063  | 
63/64 in  | 0.9844  | 25.0031  | 
1 in  | 1  | 25.4  | 
1 1/64 in  | 1.0156  | 25.7969  | 
1 1/32 in  | 1.0313  | 26.1938  | 
1 3/64 in  | 1.0469  | 26.5906  | 
1 1/16 in  | 1.0625  | 26.9875  | 
1 5/64 in  | 1.0781  | 27.3844  | 
1 3/32 in  | 1.0938  | 27.7813  | 
1 7/64 in  | 1.1094  | 28.1781  | 
1 1/8 in  | 1.125  | 28.575  | 
1 9/64 in  | 1.1406  | 28.9719  | 
1 5/32 in  | 1.1563  | 29.3688  | 
1 11/64 in  | 1.1719  | 29.7656  | 
1 3/16 in  | 1.1875  | 30.1625  | 
1 13/64 in  | 1.2031  | 30.5594  | 
1 7/32 in  | 1.2188  | 30.9563  | 
1 15/64 in  | 1.2344  | 31.3531  | 
1 1/4 in  | 1.25  | 31.75  | 
1 17/64 in  | 1.2656  | 32.1469  | 
1 9/32 in  | 1.2813  | 32.5438  | 
1 19/64 in  | 1.2969  | 32.9406  | 
1 5/16 in  | 1.3125  | 33.3375  | 
1 21/64 in  | 1.3281  | 33.7344  | 
1 11/32 in  | 1.3438  | 34.1313  | 
1 23/64 in  | 1.3594  | 34.5281  | 
1 3/8 in  | 1.375  | 34.925  | 
1 25/64 in  | 1.3906  | 35.3219  | 
1 13/32 in  | 1.4063  | 35.7188  | 
1 27/64 in  | 1.4219  | 36.1156  | 
1 7/16 in  | 1.4375  | 36.5125  | 
1 29/64 in  | 1.4531  | 36.9094  | 
1 15/32 in  | 1.4688  | 37.3063  | 
1 31/64 in  | 1.4844  | 37.7031  | 
1 1/2 in  | 1.5  | 38.1  | 
Metric Drive Size Chart
Drill size  | Diameter (in)  | Diameter (mm)  | 
0.05 mm  | 0.002  | 0.05  | 
0.1 mm  | 0.0039  | 0.1  | 
0.2 mm  | 0.0079  | 0.2  | 
0.3 mm  | 0.0118  | 0.3  | 
0.4 mm  | 0.0158  | 0.4  | 
0.5 mm  | 0.0197  | 0.5  | 
0.6 mm  | 0.0236  | 0.6  | 
0.7 mm  | 0.0276  | 0.7  | 
0.8 mm  | 0.0315  | 0.8  | 
0.9 mm  | 0.0354  | 0.9  | 
1 mm  | 0.0394  | 1  | 
1.1 mm  | 0.0433  | 1.1  | 
1.2 mm  | 0.0472  | 1.2  | 
1.3 mm  | 0.0512  | 1.3  | 
1.4 mm  | 0.0551  | 1.4  | 
1.5 mm  | 0.0591  | 1.5  | 
1.6 mm  | 0.063  | 1.6  | 
1.7 mm  | 0.0669  | 1.7  | 
1.8 mm  | 0.0709  | 1.8  | 
1.9 mm  | 0.0748  | 1.9  | 
2 mm  | 0.0787  | 2  | 
2.1 mm  | 0.0827  | 2.1  | 
2.2 mm  | 0.0866  | 2.2  | 
2.3 mm  | 0.0906  | 2.3  | 
2.4 mm  | 0.0945  | 2.4  | 
2.5 mm  | 0.0984  | 2.5  | 
2.6 mm  | 0.1024  | 2.6  | 
2.7 mm  | 0.1063  | 2.7  | 
2.8 mm  | 0.1102  | 2.8  | 
2.9 mm  | 0.1142  | 2.9  | 
3 mm  | 0.1181  | 3  | 
3.1 mm  | 0.1221  | 3.1  | 
3.2 mm  | 0.126  | 3.2  | 
3.3 mm  | 0.1299  | 3.3  | 
3.4 mm  | 0.1339  | 3.4  | 
3.5 mm  | 0.1378  | 3.5  | 
3.6 mm  | 0.1417  | 3.6  | 
3.7 mm  | 0.1457  | 3.7  | 
3.8 mm  | 0.1496  | 3.8  | 
3.9 mm  | 0.1535  | 3.9  | 
4 mm  | 0.1575  | 4  | 
4.1 mm  | 0.1614  | 4.1  | 
4.2 mm  | 0.1654  | 4.2  | 
4.3 mm  | 0.1693  | 4.3  | 
4.4 mm  | 0.1732  | 4.4  | 
4.5 mm  | 0.1772  | 4.5  | 
4.6 mm  | 0.1811  | 4.6  | 
4.7 mm  | 0.185  | 4.7  | 
4.8 mm  | 0.189  | 4.8  | 
4.9 mm  | 0.1929  | 4.9  | 
5 mm  | 0.1969  | 5  | 
5.1 mm  | 0.2008  | 5.1  | 
5.2 mm  | 0.2047  | 5.2  | 
5.3 mm  | 0.2087  | 5.3  | 
5.4 mm  | 0.2126  | 5.4  | 
5.5 mm  | 0.2165  | 5.5  | 
5.6 mm  | 0.2205  | 5.6  | 
5.7 mm  | 0.2244  | 5.7  | 
5.8 mm  | 0.2284  | 5.8  | 
5.9 mm  | 0.2323  | 5.9  | 
6 mm  | 0.2362  | 6  | 
6.1 mm  | 0.2402  | 6.1  | 
6.2 mm  | 0.2441  | 6.2  | 
6.3 mm  | 0.248  | 6.3  | 
6.4 mm  | 0.252  | 6.4  | 
6.5 mm  | 0.2559  | 6.5  | 
6.6 mm  | 0.2598  | 6.6  | 
6.7 mm  | 0.2638  | 6.7  | 
6.8 mm  | 0.2677  | 6.8  | 
6.9 mm  | 0.2717  | 6.9  | 
7 mm  | 0.2756  | 7  | 
7.1 mm  | 0.2795  | 7.1  | 
7.2 mm  | 0.2835  | 7.2  | 
7.3 mm  | 0.2874  | 7.3  | 
7.4 mm  | 0.2913  | 7.4  | 
7.5 mm  | 0.2953  | 7.5  | 
7.6 mm  | 0.2992  | 7.6  | 
7.7 mm  | 0.3032  | 7.7  | 
7.8 mm  | 0.3071  | 7.8  | 
7.9 mm  | 0.311  | 7.9  | 
8 mm  | 0.315  | 8  | 
8.1 mm  | 0.3189  | 8.1  | 
8.2 mm  | 0.3228  | 8.2  | 
8.3 mm  | 0.3268  | 8.3  | 
8.4 mm  | 0.3307  | 8.4  | 
8.5 mm  | 0.3347  | 8.5  | 
8.6 mm  | 0.3386  | 8.6  | 
8.7 mm  | 0.3425  | 8.7  | 
8.8 mm  | 0.3465  | 8.8  | 
8.9 mm  | 0.3504  | 8.9  | 
9 mm  | 0.3543  | 9  | 
9.1 mm  | 0.3583  | 9.1  | 
9.2 mm  | 0.3622  | 9.2  | 
9.3 mm  | 0.3661  | 9.3  | 
9.4 mm  | 0.3701  | 9.4  | 
9.5 mm  | 0.374  | 9.5  | 
9.6 mm  | 0.378  | 9.6  | 
9.7 mm  | 0.3819  | 9.7  | 
9.8 mm  | 0.3858  | 9.8  | 
9.9 mm  | 0.3898  | 9.9  | 
10 mm  | 0.3937  | 10  | 
10.5 mm  | 0.4134  | 10.5  | 
11 mm  | 0.4331  | 11  | 
11.5 mm  | 0.4528  | 11.5  | 
12 mm  | 0.4724  | 12  | 
12.5 mm  | 0.4921  | 12.5  | 
13 mm  | 0.5118  | 13  | 
13.5 mm  | 0.5315  | 13.5  | 
14 mm  | 0.5512  | 14  | 
14.5 mm  | 0.5709  | 14.5  | 
15 mm  | 0.5906  | 15  | 
15.5 mm  | 0.6102  | 15.5  | 
16 mm  | 0.6299  | 16  | 
16.5 mm  | 0.6496  | 16.5  | 
17 mm  | 0.6693  | 17  | 
17.5 mm  | 0.689  | 17.5  | 
18 mm  | 0.7087  | 18  | 
18.5 mm  | 0.7284  | 18.5  | 
19 mm  | 0.748  | 19  | 
19.5 mm  | 0.7677  | 19.5  | 
20 mm  | 0.7874  | 20  | 
20.5 mm  | 0.8071  | 20.5  | 
21 mm  | 0.8268  | 21  | 
21.5 mm  | 0.8465  | 21.5  | 
22 mm  | 0.8661  | 22  | 
22.5 mm  | 0.8858  | 22.5  | 
23 mm  | 0.9055  | 23  | 
23.5 mm  | 0.9252  | 23.5  | 
24 mm  | 0.9449  | 24  | 
24.5 mm  | 0.9646  | 24.5  | 
25 mm  | 0.9843  | 25  | 
25.5 mm  | 1.0039  | 25.5  | 
26 mm  | 1.0236  | 26  | 
26.5 mm  | 1.0433  | 26.5  | 
27 mm  | 1.063  | 27  | 
27.5 mm  | 1.0827  | 27.5  | 
28 mm  | 1.1024  | 28  | 
28.5 mm  | 1.1221  | 28.5  | 
29 mm  | 1.1417  | 29  | 
29.5 mm  | 1.1614  | 29.5  | 
30 mm  | 1.1811  | 30  | 
30.5 mm  | 1.2008  | 30.5  | 
31 mm  | 1.2205  | 31  | 
31.5 mm  | 1.2402  | 31.5  | 
32 mm  | 1.2598  | 32  | 
32.5 mm  | 1.2795  | 32.5  | 
33 mm  | 1.2992  | 33  | 
33.5 mm  | 1.3189  | 33.5  | 
34 mm  | 1.3386  | 34  | 
34.5 mm  | 1.3583  | 34.5  | 
35 mm  | 1.378  | 35  | 
35.5 mm  | 1.3976  | 35.5  | 
36 mm  | 1.4173  | 36  | 
36.5 mm  | 1.437  | 36.5  | 
37 mm  | 1.4567  | 37  | 
37.5 mm  | 1.4764  | 37.5  | 
38 mm  | 1.4961  | 38  | 
Letter Drill Bit Sizes
Drill  | Inch  | mm  | 
A  | 0.234  | 5.94  | 
B  | 0.238  | 6.05  | 
C  | 0.242  | 6.15  | 
D  | 0.246  | 6.25  | 
E  | 0.25  | 6.35  | 
F  | 0.257  | 6.53  | 
G  | 0.261  | 6.63  | 
H  | 0.266  | 6.76  | 
I  | 0.272  | 6.91  | 
J  | 0.277  | 7.04  | 
K  | 0.281  | 7.14  | 
L  | 0.29  | 7.37  | 
M  | 0.295  | 7.49  | 
N  | 0.302  | 7.67  | 
O  | 0.316  | 8.03  | 
P  | 0.323  | 8.2  | 
Q  | 0.332  | 8.43  | 
R  | 0.339  | 8.61  | 
S  | 0.348  | 8.84  | 
T  | 0.358  | 9.09  | 
U  | 0.368  | 9.35  | 
V  | 0.377  | 9.58  | 
W  | 0.386  | 9.8  | 
X  | 0.397  | 10.08  | 
Y  | 0.404  | 10.26  | 
Z  | 0.413  | 10.49  | 
Wire Gauge Size Chart
Drill size  | Diameter (in)  | Diameter (mm)  | 
#107  | 0.0019  | 0.0483  | 
#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  | 
#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  | 0.16  | 
#95  | 0.0067  | 0.1702  | 
#94  | 0.0071  | 0.1803  | 
#93  | 0.0075  | 0.1905  | 
#92  | 0.0079  | 0.2007  | 
#91  | 0.0083  | 0.2108  | 
#90  | 0.0087  | 0.221  | 
#89  | 0.0091  | 0.2311  | 
#88  | 0.0095  | 0.2413  | 
#87  | 0.01  | 0.254  | 
#86  | 0.0105  | 0.2667  | 
#85  | 0.011  | 0.2794  | 
#84  | 0.0115  | 0.2921  | 
#83  | 0.012  | 0.3048  | 
#82  | 0.0125  | 0.3175  | 
#81  | 0.013  | 0.3302  | 
#80  | 0.0135  | 0.3429  | 
#79  | 0.0145  | 0.368  | 
#78  | 0.016  | 0.4064  | 
#77  | 0.018  | 0.4572  | 
#76  | 0.02  | 0.508  | 
#75  | 0.021  | 0.5334  | 
#74  | 0.0225  | 0.5715  | 
#73  | 0.024  | 0.6096  | 
#72  | 0.025  | 0.635  | 
#71  | 0.026  | 0.6604  | 
#70  | 0.028  | 0.7112  | 
#69  | 0.0292  | 0.7417  | 
#68  | 0.031  | 0.7874  | 
#67  | 0.032  | 0.8128  | 
#66  | 0.033  | 0.8382  | 
#65  | 0.035  | 0.889  | 
#64  | 0.036  | 0.9144  | 
#63  | 0.037  | 0.9398  | 
#62  | 0.038  | 0.9652  | 
#61  | 0.039  | 0.9906  | 
#60  | 0.04  | 1.016  | 
#59  | 0.041  | 1.0414  | 
#58  | 0.042  | 1.0668  | 
#57  | 0.043  | 1.0922  | 
#56  | 0.0465  | 1.1811  | 
#55  | 0.052  | 1.3208  | 
#54  | 0.055  | 1.397  | 
#53  | 0.0595  | 1.5113  | 
#52  | 0.0635  | 1.6129  | 
#51  | 0.067  | 1.7018  | 
#50  | 0.07  | 1.778  | 
#49  | 0.073  | 1.8542  | 
#48  | 0.076  | 1.9304  | 
#47  | 0.0785  | 1.9939  | 
#46  | 0.081  | 2.0574  | 
#45  | 0.082  | 2.0828  | 
#44  | 0.086  | 2.1844  | 
#43  | 0.089  | 2.2606  | 
#42  | 0.0935  | 2.3749  | 
#41  | 0.096  | 2.4384  | 
#40  | 0.098  | 2.4892  | 
#39  | 0.0995  | 2.5273  | 
#38  | 0.1015  | 2.5781  | 
#37  | 0.104  | 2.6416  | 
#36  | 0.1065  | 2.7051  | 
#35  | 0.11  | 2.794  | 
#34  | 0.111  | 2.8194  | 
#33  | 0.113  | 2.8702  | 
#32  | 0.116  | 2.9464  | 
#31  | 0.12  | 3.048  | 
#30  | 0.1285  | 3.2639  | 
#29  | 0.136  | 3.4544  | 
#28  | 0.1405  | 3.5687  | 
#27  | 0.144  | 3.6576  | 
#26  | 0.147  | 3.7338  | 
#25  | 0.1495  | 3.7973  | 
#24  | 0.152  | 3.8608  | 
#23  | 0.154  | 3.9116  | 
#22  | 0.157  | 3.9878  | 
#21  | 0.159  | 4.0386  | 
#20  | 0.161  | 4.0894  | 
#19  | 0.166  | 4.2164  | 
#18  | 0.1695  | 4.3053  | 
#17  | 0.173  | 4.3942  | 
#16  | 0.177  | 4.4958  | 
#15  | 0.18  | 4.572  | 
#14  | 0.182  | 4.6228  | 
#13  | 0.185  | 4.699  | 
#12  | 0.189  | 4.8006  | 
#11  | 0.191  | 4.8514  | 
#10  | 0.1935  | 4.9149  | 
#9  | 0.196  | 4.9784  | 
#8  | 0.199  | 5.0546  | 
#7  | 0.201  | 5.1054  | 
#6  | 0.204  | 5.1816  | 
#5  | 0.2055  | 5.2197  | 
#4  | 0.209  | 5.3086  | 
#3  | 0.213  | 5.4102  | 
#2  | 0.221  | 5.6134  | 
#1  | 0.228  | 5.7912  | 
