Tap & drill sizes, decimal equivalents.
A complete reference for fractional, wire gauge, letter, and metric drill sizes from #80 to 1". Browse the full chart below, or order the pocket-sized Champion Cutting Tool card to keep on your bench, in your toolbox, or in your shirt pocket.
Champion Cutting Tool's printed reference card, ships from stock at all 21 branches.
Every size, on one chart.
220 entries across fractional, wire gauge (#1 to #80), letter (A to Z), and metric (0.50mm to 25.00mm) drill sizes. Sorted by decimal equivalent from smallest to largest.
| Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal |
|---|---|---|---|---|---|---|---|
| 80 | .0135 | 37 | .1040 | C | .2420 | 17/32" | .5312 |
| 79 | .0145 | 36 | .1065 | D | .2460 | 13.50mm | .5315 |
| 1/64" | .0156 | 7/64" | .1094 | 1/4" | .2500 | 35/64" | .5469 |
| 78 | .0160 | 35 | .1100 | 6.50mm | .2559 | 14.00mm | .5512 |
| 77 | .0180 | 34 | .1110 | F | .2570 | 9/16" | .5625 |
| 0.50mm | .0197 | 33 | .1130 | G | .2610 | 14.50mm | .5709 |
| 76 | .0200 | 32 | .1160 | 17/64" | .2656 | 37/64" | .5781 |
| 75 | .0210 | 3.00mm | .1181 | H | .2660 | 15.00mm | .5906 |
| 74 | .0225 | 31 | .1200 | I | .2720 | 19/32" | .5938 |
| 73 | .0240 | 1/8" | .1250 | 7.00mm | .2756 | 39/64" | .6094 |
| 72 | .0250 | 30 | .1285 | J | .2770 | 15.50mm | .6102 |
| 71 | .0260 | 29 | .1360 | K | .2810 | 5/8" | .6250 |
| 70 | .0280 | 3.50mm | .1378 | 9/32" | .2812 | 16.00mm | .6299 |
| 69 | .0292 | 28 | .1405 | L | .2900 | 41/64" | .6406 |
| 68 | .0310 | 9/64" | .1406 | M | .2950 | 16.50mm | .6496 |
| 1/32" | .0312 | 27 | .1440 | 7.50mm | .2953 | 21/32" | .6562 |
| 67 | .0320 | 26 | .1470 | 19/64" | .2969 | 17.00mm | .6693 |
| 66 | .0330 | 25 | .1495 | N | .3020 | 43/64" | .6719 |
| 65 | .0350 | 24 | .1520 | 5/16" | .3125 | 11/16" | .6875 |
| 64 | .0360 | 23 | .1540 | 8.00mm | .3150 | 17.50mm | .6890 |
| 63 | .0370 | 5/32" | .1562 | O | .3160 | 45/64" | .7031 |
| 62 | .0380 | 22 | .1570 | P | .3230 | 18.00mm | .7087 |
| 61 | .0390 | 4.00mm | .1575 | 21/64" | .3281 | 23/32" | .7188 |
| 1.00mm | .0394 | 21 | .1590 | Q | .3320 | 18.50mm | .7283 |
| 60 | .0400 | 20 | .1610 | 8.50mm | .3346 | 47/64" | .7344 |
| 59 | .0410 | 19 | .1660 | R | .3390 | 19.00mm | .7480 |
| 58 | .0420 | 18 | .1695 | 11/32" | .3438 | 3/4" | .7500 |
| 57 | .0430 | 4.50mm | .1719 | S | .3480 | 49/64" | .7656 |
| 56 | .0465 | 17 | .1730 | 9.00mm | .3543 | 19.50mm | .7677 |
| 3/64" | .0469 | 16 | .1770 | T | .3580 | 25/32" | .7812 |
| 55 | .0520 | 4.50mm | .1772 | 23/64" | .3594 | 20.00mm | .7874 |
| 54 | .0550 | 15 | .1800 | U | .3680 | 51/64" | .7969 |
| 1.50mm | .0591 | 14 | .1820 | 9.50mm | .3740 | 20.50mm | .8071 |
| 53 | .0595 | 13 | .1850 | 3/8" | .3750 | 13/16" | .8125 |
| 1/16" | .0625 | 3/16" | .1875 | V | .3770 | 21.00mm | .8268 |
| 52 | .0635 | 12 | .1890 | W | .3860 | 53/64" | .8281 |
| 1.70mm | .0669 | 11 | .1910 | 25/64" | .3906 | 27/32" | .8438 |
| 51 | .0670 | 10 | .1935 | 10.00mm | .3937 | 21.50mm | .8465 |
| 50 | .0700 | 9 | .1960 | X | .3970 | 55/64" | .8594 |
| 49 | .0730 | 5.00mm | .1969 | Y | .4040 | 22.00mm | .8661 |
| 48 | .0760 | 8 | .1990 | 13/32" | .4062 | 7/8" | .8750 |
| 5/64" | .0781 | 7 | .2010 | Z | .4130 | 22.50mm | .8858 |
| 47 | .0785 | 13/64" | .2031 | 10.50mm | .4134 | 57/64" | .8906 |
| 2.00mm | .0787 | 6 | .2040 | 27/64" | .4219 | 23.00mm | .9055 |
| 46 | .0810 | 5 | .2055 | 11.00mm | .4331 | 29/32" | .9062 |
| 45 | .0820 | 4 | .2090 | 7/16" | .4375 | 59/64" | .9219 |
| 44 | .0860 | 3 | .2130 | 11.50mm | .4528 | 23.50mm | .9252 |
| 43 | .0890 | 5.50mm | .2165 | 29/64" | .4531 | 15/16" | .9375 |
| 42 | .0935 | 7/32" | .2188 | 15/32" | .4688 | 24.00mm | .9449 |
| 3/32" | .0938 | 2 | .2210 | 12.00mm | .4724 | 61/64" | .9531 |
| 41 | .0960 | 1 | .2280 | 31/64" | .4844 | 24.50mm | .9646 |
| 40 | .0980 | A | .2340 | 12.50mm | .4921 | 31/32" | .9688 |
| 2.50mm | .0984 | 15/64" | .2344 | 1/2" | .5000 | 25.00mm | .9843 |
| 39 | .0995 | 6.00mm | .2362 | 13.00mm | .5118 | 63/64" | .9844 |
| 38 | .1015 | B | .2380 | 33/64" | .5156 | 1" | 1.0000 |
Quick reference, by category.
Drill sizes are organized into four standard groupings. Use the decimal equivalent column to cross-reference between systems or to spec the right hole for a tap.
How to Read This Chart
Find your required drill size in the left column, then read the decimal equivalent in inches. Use the decimal to select the correct bit from your set or to spec the hole for a tap.
Wire Gauge (#1 to #80)
Wire gauge sizes run inverse to diameter, #80 is the smallest at .0135" and #1 is the largest at .2280". Common in precision machining, electronics, and instrument work.
Letter Sizes (A to Z)
Letter drills fill the gap between fractional sizes from .234" (A) to .413" (Z). Useful when you need an exact diameter that doesn't fall on a standard fractional increment.
Fractional Sizes
Fractional drills run from 1/64" (.0156") to 1" (1.0000") in 64ths increments. The most common category for general shop and construction use.
Metric Sizes
Metric sizes from 0.50mm to 25.00mm are interleaved with the chart so you can quickly compare metric to fractional equivalents. Essential for imported hardware and metric fasteners.
Tap Drill Selection
For tapping, choose a drill size approximately 75% of thread depth. The decimal equivalent lets you cross-reference tap drill charts for any thread standard, including UNC, UNF, and metric.
Pick one up at any branch.
Champion Cutting Tool's tap and drill reference card (SKU 342-601) is stocked at all 21 Tacoma Screw Products locations across WA, OR, ID, and MT. Call ahead, walk in, or order online.