Drill Size Chart
Full drill size reference (fractional, number (#1–#80), letter (A–Z), and metric) each with exact decimal-inch and millimeter values. Find the nearest drill to any target hole, in your browser.
Nearest standard drill
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Drill size reference
| Size | Type | Inch | mm |
|---|---|---|---|
| #80 | number | 0.0135 | 0.343 |
| #79 | number | 0.0145 | 0.368 |
| 1/64" | fraction | 0.0156 | 0.397 |
| #78 | number | 0.0160 | 0.406 |
| #77 | number | 0.0180 | 0.457 |
| 0.5 mm | metric | 0.0197 | 0.500 |
| #76 | number | 0.0200 | 0.508 |
| #75 | number | 0.0210 | 0.533 |
| #74 | number | 0.0225 | 0.571 |
| #73 | number | 0.0240 | 0.610 |
| #72 | number | 0.0250 | 0.635 |
| #71 | number | 0.0260 | 0.660 |
| #70 | number | 0.0280 | 0.711 |
| #69 | number | 0.0292 | 0.742 |
| #68 | number | 0.0310 | 0.787 |
| 1/32" | fraction | 0.0313 | 0.794 |
| #67 | number | 0.0320 | 0.813 |
| #66 | number | 0.0330 | 0.838 |
| #65 | number | 0.0350 | 0.889 |
| #64 | number | 0.0360 | 0.914 |
| #63 | number | 0.0370 | 0.940 |
| #62 | number | 0.0380 | 0.965 |
| #61 | number | 0.0390 | 0.991 |
| 1 mm | metric | 0.0394 | 1.000 |
| #60 | number | 0.0400 | 1.016 |
| #59 | number | 0.0410 | 1.041 |
| #58 | number | 0.0420 | 1.067 |
| #57 | number | 0.0430 | 1.092 |
| #56 | number | 0.0465 | 1.181 |
| 3/64" | fraction | 0.0469 | 1.191 |
| #55 | number | 0.0520 | 1.321 |
| #54 | number | 0.0550 | 1.397 |
| 1.5 mm | metric | 0.0591 | 1.500 |
| #53 | number | 0.0595 | 1.511 |
| 1/16" | fraction | 0.0625 | 1.587 |
| #52 | number | 0.0635 | 1.613 |
| #51 | number | 0.0670 | 1.702 |
| #50 | number | 0.0700 | 1.778 |
| #49 | number | 0.0730 | 1.854 |
| #48 | number | 0.0760 | 1.930 |
| 5/64" | fraction | 0.0781 | 1.984 |
| #47 | number | 0.0785 | 1.994 |
| 2 mm | metric | 0.0787 | 2.000 |
| #46 | number | 0.0810 | 2.057 |
| #45 | number | 0.0820 | 2.083 |
| #44 | number | 0.0860 | 2.184 |
| #43 | number | 0.0890 | 2.261 |
| #42 | number | 0.0935 | 2.375 |
| 3/32" | fraction | 0.0938 | 2.381 |
| #41 | number | 0.0960 | 2.438 |
| #40 | number | 0.0980 | 2.489 |
| 2.5 mm | metric | 0.0984 | 2.500 |
| #39 | number | 0.0995 | 2.527 |
| #38 | number | 0.1015 | 2.578 |
| #37 | number | 0.1040 | 2.642 |
| #36 | number | 0.1065 | 2.705 |
| 7/64" | fraction | 0.1094 | 2.778 |
| #35 | number | 0.1100 | 2.794 |
| #34 | number | 0.1110 | 2.819 |
| #33 | number | 0.1130 | 2.870 |
| #32 | number | 0.1160 | 2.946 |
| 3 mm | metric | 0.1181 | 3.000 |
| #31 | number | 0.1200 | 3.048 |
| 1/8" | fraction | 0.1250 | 3.175 |
| #30 | number | 0.1285 | 3.264 |
| #29 | number | 0.1360 | 3.454 |
| 3.5 mm | metric | 0.1378 | 3.500 |
| #28 | number | 0.1405 | 3.569 |
| 9/64" | fraction | 0.1406 | 3.572 |
| #27 | number | 0.1440 | 3.658 |
| #26 | number | 0.1470 | 3.734 |
| #25 | number | 0.1495 | 3.797 |
| #24 | number | 0.1520 | 3.861 |
| #23 | number | 0.1540 | 3.912 |
| 5/32" | fraction | 0.1563 | 3.969 |
| #22 | number | 0.1570 | 3.988 |
| 4 mm | metric | 0.1575 | 4.000 |
| #21 | number | 0.1590 | 4.039 |
| #20 | number | 0.1610 | 4.089 |
| #19 | number | 0.1660 | 4.216 |
| #18 | number | 0.1695 | 4.305 |
| 11/64" | fraction | 0.1719 | 4.366 |
| #17 | number | 0.1730 | 4.394 |
| #16 | number | 0.1770 | 4.496 |
| 4.5 mm | metric | 0.1772 | 4.500 |
| #15 | number | 0.1800 | 4.572 |
| #14 | number | 0.1820 | 4.623 |
| #13 | number | 0.1850 | 4.699 |
| 3/16" | fraction | 0.1875 | 4.762 |
| #12 | number | 0.1890 | 4.801 |
| #11 | number | 0.1910 | 4.851 |
| #10 | number | 0.1935 | 4.915 |
| #9 | number | 0.1960 | 4.978 |
| 5 mm | metric | 0.1969 | 5.000 |
| #8 | number | 0.1990 | 5.055 |
| #7 | number | 0.2010 | 5.105 |
| 13/64" | fraction | 0.2031 | 5.159 |
| #6 | number | 0.2040 | 5.182 |
| #5 | number | 0.2055 | 5.220 |
| #4 | number | 0.2090 | 5.309 |
| #3 | number | 0.2130 | 5.410 |
| 5.5 mm | metric | 0.2165 | 5.500 |
| 7/32" | fraction | 0.2188 | 5.556 |
| #2 | number | 0.2210 | 5.613 |
| #1 | number | 0.2280 | 5.791 |
| A | letter | 0.2340 | 5.944 |
| 15/64" | fraction | 0.2344 | 5.953 |
| 6 mm | metric | 0.2362 | 6.000 |
| B | letter | 0.2380 | 6.045 |
| C | letter | 0.2420 | 6.147 |
| D | letter | 0.2460 | 6.248 |
| 1/4" | fraction | 0.2500 | 6.350 |
| E | letter | 0.2500 | 6.350 |
| 6.5 mm | metric | 0.2559 | 6.500 |
| F | letter | 0.2570 | 6.528 |
| G | letter | 0.2610 | 6.629 |
| 17/64" | fraction | 0.2656 | 6.747 |
| H | letter | 0.2660 | 6.756 |
| I | letter | 0.2720 | 6.909 |
| 7 mm | metric | 0.2756 | 7.000 |
| J | letter | 0.2770 | 7.036 |
| K | letter | 0.2810 | 7.137 |
| 9/32" | fraction | 0.2813 | 7.144 |
| L | letter | 0.2900 | 7.366 |
| M | letter | 0.2950 | 7.493 |
| 7.5 mm | metric | 0.2953 | 7.500 |
| 19/64" | fraction | 0.2969 | 7.541 |
| N | letter | 0.3020 | 7.671 |
| 5/16" | fraction | 0.3125 | 7.938 |
| 8 mm | metric | 0.3150 | 8.000 |
| O | letter | 0.3160 | 8.026 |
| P | letter | 0.3230 | 8.204 |
| 21/64" | fraction | 0.3281 | 8.334 |
| Q | letter | 0.3320 | 8.433 |
| 8.5 mm | metric | 0.3346 | 8.500 |
| R | letter | 0.3390 | 8.611 |
| 11/32" | fraction | 0.3438 | 8.731 |
| S | letter | 0.3480 | 8.839 |
| 9 mm | metric | 0.3543 | 9.000 |
| T | letter | 0.3580 | 9.093 |
| 23/64" | fraction | 0.3594 | 9.128 |
| U | letter | 0.3680 | 9.347 |
| 9.5 mm | metric | 0.3740 | 9.500 |
| 3/8" | fraction | 0.3750 | 9.525 |
| V | letter | 0.3770 | 9.576 |
| W | letter | 0.3860 | 9.804 |
| 25/64" | fraction | 0.3906 | 9.922 |
| 10 mm | metric | 0.3937 | 10.000 |
| X | letter | 0.3970 | 10.084 |
| Y | letter | 0.4040 | 10.262 |
| 13/32" | fraction | 0.4063 | 10.319 |
| Z | letter | 0.4130 | 10.490 |
| 10.5 mm | metric | 0.4134 | 10.500 |
| 27/64" | fraction | 0.4219 | 10.716 |
| 11 mm | metric | 0.4331 | 11.000 |
| 7/16" | fraction | 0.4375 | 11.112 |
| 11.5 mm | metric | 0.4528 | 11.500 |
| 29/64" | fraction | 0.4531 | 11.509 |
| 15/32" | fraction | 0.4688 | 11.906 |
| 12 mm | metric | 0.4724 | 12.000 |
| 31/64" | fraction | 0.4844 | 12.303 |
| 12.5 mm | metric | 0.4921 | 12.500 |
| 1/2" | fraction | 0.5000 | 12.700 |
| 13 mm | metric | 0.5118 | 13.000 |
| 33/64" | fraction | 0.5156 | 13.097 |
| 17/32" | fraction | 0.5313 | 13.494 |
| 35/64" | fraction | 0.5469 | 13.891 |
| 14 mm | metric | 0.5512 | 14.000 |
| 9/16" | fraction | 0.5625 | 14.287 |
| 37/64" | fraction | 0.5781 | 14.684 |
| 15 mm | metric | 0.5906 | 15.000 |
| 19/32" | fraction | 0.5938 | 15.081 |
| 39/64" | fraction | 0.6094 | 15.478 |
| 5/8" | fraction | 0.6250 | 15.875 |
| 16 mm | metric | 0.6299 | 16.000 |
| 41/64" | fraction | 0.6406 | 16.272 |
| 21/32" | fraction | 0.6563 | 16.669 |
| 43/64" | fraction | 0.6719 | 17.066 |
| 11/16" | fraction | 0.6875 | 17.462 |
| 45/64" | fraction | 0.7031 | 17.859 |
| 18 mm | metric | 0.7087 | 18.000 |
| 23/32" | fraction | 0.7188 | 18.256 |
| 47/64" | fraction | 0.7344 | 18.653 |
| 3/4" | fraction | 0.7500 | 19.050 |
| 49/64" | fraction | 0.7656 | 19.447 |
| 25/32" | fraction | 0.7813 | 19.844 |
| 20 mm | metric | 0.7874 | 20.000 |
| 51/64" | fraction | 0.7969 | 20.241 |
| 13/16" | fraction | 0.8125 | 20.637 |
| 53/64" | fraction | 0.8281 | 21.034 |
| 27/32" | fraction | 0.8438 | 21.431 |
| 55/64" | fraction | 0.8594 | 21.828 |
| 7/8" | fraction | 0.8750 | 22.225 |
| 57/64" | fraction | 0.8906 | 22.622 |
| 29/32" | fraction | 0.9063 | 23.019 |
| 59/64" | fraction | 0.9219 | 23.416 |
| 15/16" | fraction | 0.9375 | 23.813 |
| 61/64" | fraction | 0.9531 | 24.209 |
| 31/32" | fraction | 0.9688 | 24.606 |
| 63/64" | fraction | 0.9844 | 25.003 |
| 1" | fraction | 1.0000 | 25.400 |
No drill matches your filters.
About drill sizes
Standard drills come in four overlapping systems: fractional inch (1/64″ steps), number/wire gauge (#1–#80), letter (A–Z), and metric. This chart lists each with its exact decimal-inch and millimetre equivalent, so you can cross over between systems or pick the closest available bit for a target hole.
Fractional and metric sizes are exact by definition; number and letter sizes use the published ANSI decimal-inch values. The millimetre column uses the exact 25.4 mm/inch factor.
What this does
This reference lists every standard drill size (fractional, number (#1–#80), letter (A–Z), and metric) each with its exact decimal-inch and millimeter value, and finds the nearest drill to any target hole.
How to use it
- Browse or search the four size systems.
- Or enter a target size in inches or mm.
- Read the closest standard drill and its offset.
- Decide whether to size up or down.
How it works
Four overlapping systems cover the gaps between sizes: fractional inch in 1/64-inch steps, number/wire gauge (#1–#80), letter (A–Z), and common metric drills. The nearest-drill search scans them all and shows how far each is from your target.
Understanding your result
The nearest-drill result shows the closest standard size to your target and how far off it sits, so you can judge whether that gap matters for the fit. For a clearance hole a slightly larger drill is fine; for a press or tap fit, favour the size that errs small.
Example
A 1/4-inch drill is 0.250 inch. The nearest drill to 5 mm (0.1969 inch) is a #9 (0.1960 inch).
Sources & methodology
Last updated .
Frequently asked questions
What drill size systems are covered?
Four overlapping systems: fractional inch (1/64″ steps), number/wire gauge (#1–#80), letter (A–Z), and common metric sizes, all listed with decimal-inch and millimeter equivalents.
How does “find the nearest drill” work?
Enter a target size in inches or millimeters and the tool scans every standard drill for the closest match, showing how far off it is so you can decide whether to size up or down.
Is my data stored?
No. Everything is calculated locally in your browser.
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