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 | 
 
 
