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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.

Downloadable versions:
Drill Size Chart (English) English Drill Size Chart (Metric) Metric
 

Drill size standard:

Drill size Diameter (in) Diameter (mm)
#1070.00190.0483
0.05 mm0.00200.0500
#1060.00230.0584
#1050.00270.0686
#1040.00310.0787
#1030.00350.0889
#1020.00390.0991
0.1 mm0.00390.1000
#1010.00430.1092
#1000.00470.1194
#990.00510.1295
#980.00550.1397
#970.00590.1499
#960.00630.1600
#950.00670.1702
#940.00710.1803
#930.00750.1905
0.2 mm0.00790.2000
#920.00790.2007
#910.00830.2108
#900.00870.2210
#890.00910.2311
#880.00950.2413
#870.01000.2540
#860.01050.2667
#850.01100.2794
#840.01150.2921
0.3 mm0.01180.3000
#830.01200.3048
#820.01250.3175
#810.01300.3302
#800.01350.3429
#790.01450.3680
1/64 in0.01560.3969
0.4 mm0.01580.4000
#780.01600.4064
#770.01800.4572
0.5 mm0.01970.5000
#760.02000.5080
#750.02100.5334
#740.02250.5715
0.6 mm0.02360.6000
#730.02400.6096
#720.02500.6350
#710.02600.6604
0.7 mm0.02760.7000
#700.02800.7112
#690.02920.7417
#680.03100.7874
1/32 in0.03130.7938
0.8 mm0.03150.8000
#670.03200.8128
#660.03300.8382
#650.03500.8890
0.9 mm0.03540.9000
#640.03600.9144
#630.03700.9398
#620.03800.9652
#610.03900.9906
1 mm0.03941.0000
#600.04001.0160
#590.04101.0414
#580.04201.0668
#570.04301.0922
1.1 mm0.04331.1000
#560.04651.1811
3/64 in0.04691.1906
1.2 mm0.04721.2000
1.3 mm0.05121.3000
#550.05201.3208
#540.05501.3970
1.4 mm0.05511.4000
1.5 mm0.05911.5000
#530.05951.5113
1/16 in0.06251.5875
1.6 mm0.06301.6000
#520.06351.6129
1.7 mm0.06691.7000
#510.06701.7018
#500.07001.7780
1.8 mm0.07091.8000
#490.07301.8542
1.9 mm0.07481.9000
#480.07601.9304
5/64 in0.07811.9844
#470.07851.9939
2 mm0.07872.0000
#460.08102.0574
#450.08202.0828
2.1 mm0.08272.1000
#440.08602.1844
2.2 mm0.08662.2000
#430.08902.2606
2.3 mm0.09062.3000
#420.09352.3749
3/32 in0.09382.3813
2.4 mm0.09452.4000
#410.09602.4384
#400.09802.4892
2.5 mm0.09842.5000
#390.09952.5273
#380.10152.5781
2.6 mm0.10242.6000
#370.10402.6416
2.7 mm0.10632.7000
#360.10652.7051
7/64 in0.10942.7781
#350.11002.7940
2.8 mm0.11022.8000
#340.11102.8194
#330.11302.8702
2.9 mm0.11422.9000
#320.11602.9464
3 mm0.11813.0000
#310.12003.0480
3.1 mm0.12213.1000
1/8 in0.12503.1750
3.2 mm0.12603.2000
#300.12853.2639
3.3 mm0.12993.3000
3.4 mm0.13393.4000
#290.13603.4544
3.5 mm0.13783.5000
#280.14053.5687
9/64 in0.14063.5719
3.6 mm0.14173.6000
#270.14403.6576
3.7 mm0.14573.7000
#260.14703.7338
#250.14953.7973
3.8 mm0.14963.8000
#240.15203.8608
3.9 mm0.15353.9000
#230.15403.9116
5/32 in0.15633.9688
#220.15703.9878
4 mm0.15754.0000
#210.15904.0386
#200.16104.0894
4.1 mm0.16144.1000
4.2 mm0.16544.2000
#190.16604.2164
4.3 mm0.16934.3000
#180.16954.3053
11/64 in0.17194.3656
#170.17304.3942
4.4 mm0.17324.4000
#160.17704.4958
4.5 mm0.17724.5000
#150.18004.5720
4.6 mm0.18114.6000
#140.18204.6228
#130.18504.6990
4.7 mm0.18504.7000
3/16 in0.18754.7625
4.8 mm0.18904.8000
#120.18904.8006
#110.19104.8514
4.9 mm0.19294.9000
#100.19354.9149
#90.19604.9784
5 mm0.19695.0000
#80.19905.0546
5.1 mm0.20085.1000
#70.20105.1054
13/64 in0.20315.1594
#60.20405.1816
5.2 mm0.20475.2000
#50.20555.2197
5.3 mm0.20875.3000
#40.20905.3086
5.4 mm0.21265.4000
#30.21305.4102
5.5 mm0.21655.5000
7/32 in0.21885.5563
5.6 mm0.22055.6000
#20.22105.6134
5.7 mm0.22445.7000
#10.22805.7912
5.8 mm0.22845.8000
5.9 mm0.23235.9000
A0.23405.9436
15/64 in0.23445.9531
6 mm0.23626.0000
B0.23806.0452
6.1 mm0.24026.1000
C0.24206.1468
6.2 mm0.24416.2000
D0.24606.2484
6.3 mm0.24806.3000
1/4 in0.25006.3500
E0.25006.3500
6.4 mm0.25206.4000
6.5 mm0.25596.5000
F0.25706.5278
6.6 mm0.25986.6000
G0.26106.6294
6.7 mm0.26386.7000
17/64 in0.26566.7469
H0.26606.7564
6.8 mm0.26776.8000
6.9 mm0.27176.9000
I0.27206.9088
7 mm0.27567.0000
J0.27707.0358
7.1 mm0.27957.1000
K0.28107.1374
9/32 in0.28137.1438
7.2 mm0.28357.2000
7.3 mm0.28747.3000
L0.29007.3660
7.4 mm0.29137.4000
M0.29507.4930
7.5 mm0.29537.5000
19/64 in0.29697.5406
7.6 mm0.29927.6000
N0.30207.6708
7.7 mm0.30327.7000
7.8 mm0.30717.8000
7.9 mm0.31107.9000
5/16 in0.31257.9375
8 mm0.31508.0000
O0.31608.0264
8.1 mm0.31898.1000
8.2 mm0.32288.2000
P0.32308.2042
8.3 mm0.32688.3000
21/64 in0.32818.3344
8.4 mm0.33078.4000
Q0.33208.4328
8.5 mm0.33478.5000
8.6 mm0.33868.6000
R0.33908.6106
8.7 mm0.34258.7000
11/32 in0.34388.7313
8.8 mm0.34658.8000
S0.34808.8392
8.9 mm0.35048.9000
9 mm0.35439.0000
T0.35809.0932
9.1 mm0.35839.1000
23/64 in0.35949.1281
9.2 mm0.36229.2000
9.3 mm0.36619.3000
U0.36809.3472
9.4 mm0.37019.4000
9.5 mm0.37409.5000
3/8 in0.37509.5250
V0.37709.5758
9.6 mm0.37809.6000
9.7 mm0.38199.7000
9.8 mm0.38589.8000
W0.38609.8044
9.9 mm0.38989.9000
25/64 in0.39069.9219
10 mm0.393710.0000
X0.397010.0838
Y0.404010.2616
13/32 in0.406310.3188
Z0.413010.4902
10.5 mm0.413410.5000
27/64 in0.421910.7156
11 mm0.433111.0000
7/16 in0.437511.1125
11.5 mm0.452811.5000
29/64 in0.453111.5094
15/32 in0.468811.9063
12 mm0.472412.0000
31/64 in0.484412.3031
12.5 mm0.492112.5000
1/2 in0.500012.7000
13 mm0.511813.0000
33/64 in0.515613.0969
17/32 in0.531313.4938
13.5 mm0.531513.5000
35/64 in0.546913.8906
14 mm0.551214.0000
9/16 in0.562514.2875
14.5 mm0.570914.5000
37/64 in0.578114.6844
15 mm0.590615.0000
19/32 in0.593815.0813
39/64 in0.609415.4781
15.5 mm0.610215.5000
5/8 in0.625015.8750
16 mm0.629916.0000
41/64 in0.640616.2719
16.5 mm0.649616.5000
17 mm0.669317.0000
43/64 in0.671917.0656
11/16 in0.687517.4625
17.5 mm0.689017.5000
45/64 in0.703117.8594
18 mm0.708718.0000
23/32 in0.718818.2563
18.5 mm0.728418.5000
47/64 in0.734418.6531
19 mm0.748019.0000
3/4 in0.750019.0500
49/64 in0.765619.4469
19.5 mm0.767719.5000
25/32 in0.781319.8438
20 mm0.787420.0000
51/64 in0.796920.2406
20.5 mm0.807120.5000
13/16 in0.812520.6375
21 mm0.826821.0000
53/64 in0.828121.0344
27/32 in0.843821.4313
21.5 mm0.846521.5000
55/64 in0.859421.8281
22 mm0.866122.0000
7/8 in0.875022.2250
22.5 mm0.885822.5000
57/64 in0.890622.6219
23 mm0.905523.0000
29/32 in0.906323.0188
21/23 in0.913023.1913
59/64 in0.921923.4156
23.5 mm0.925223.5000
15/16 in0.937523.8125
24 mm0.944924.0000
61/64 in0.953124.2094
24.5 mm0.964624.5000
31/32 in0.968824.6063
25 mm0.984325.0000
63/64 in0.984425.0031
1 in1.000025.4000
25.5 mm1.003925.5000
1 1/64 in1.015625.7969
26 mm1.023626.0000
1 1/32 in1.031326.1938
26.5 mm1.043326.5000
1 3/64 in1.046926.5906
1 1/16 in1.062526.9875
27 mm1.063027.0000
1 5/64 in1.078127.3844
27.5 mm1.082727.5000
1 3/32 in1.093827.7813
28 mm1.102428.0000
1 7/64 in1.109428.1781
28.5 mm1.122128.5000
1 1/8 in1.125028.5750
1 9/64 in1.140628.9719
29 mm1.141729.0000
1 5/32 in1.156329.3688
29.5 mm1.161429.5000
1 11/64 in1.171929.7656
30 mm1.181130.0000
1 3/16 in1.187530.1625
30.5 mm1.200830.5000
1 13/64 in1.203130.5594
1 7/32 in1.218830.9563
31 mm1.220531.0000
1 15/64 in1.234431.3531
31.5 mm1.240231.5000
1 1/4 in1.250031.7500
32 mm1.259832.0000
1 17/64 in1.265632.1469
32.5 mm1.279532.5000
1 9/32 in1.281332.5438
1 19/64 in1.296932.9406
33 mm1.299233.0000
1 5/16 in1.312533.3375
33.5 mm1.318933.5000
1 21/64 in1.328133.7344
34 mm1.338634.0000
1 11/32 in1.343834.1313
34.5 mm1.358334.5000
1 23/64 in1.359434.5281
1 3/8 in1.375034.9250
35 mm1.378035.0000
1 25/64 in1.390635.3219
35.5 mm1.397635.5000
1 13/32 in1.406335.7188
36 mm1.417336.0000
1 27/64 in1.421936.1156
36.5 mm1.437036.5000
1 7/16 in1.437536.5125
1 29/64 in1.453136.9094
37 mm1.456737.0000
1 15/32 in1.468837.3063
37.5 mm1.476437.5000
1 31/64 in1.484437.7031
38 mm1.496138.0000
1 1/2 in1.500038.1000

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