Need some help with size conversions? Check out our Metric, Wire Gauge, & Decimal Conversion Chart. Understanding the precise measurements and decimal equivalents of tap drill sizes is essential for accurate and snug fits in various applications.
| Drill Size | Decimal | Drill Size | Decimal | Drill Size | Decimal | Drill Size | Decimal |
| 1/64" | 0.0156 | 26 | 0.1470 | K | 0.2810 | 37/64" | 0.5781 |
| 0.5mm | 0.0197 | 25 | 0.1495 | 9/32" | 0.2812 | 15mm | 0.5906 |
| 1/32" | 0.0312 | 24 | 0.1520 | L | 0.2900 | 19/32" | 0.5938 |
| 1mm | 0.0394 | 23 | 0.1540 | M | 0.2950 | 39/64" | 0.6094 |
| 60 | 0.0400 | 5/32" | 0.1562 | 7.5mm | 0.2953 | 15.5mm | 0.6102 |
| 59 | 0.0410 | 22 | 0.1570 | 19/64" | 0.2969 | 5/8" | 0.6250 |
| 58 | 0.0420 | 4mm | 0.1575 | N | 0.3020 | 16mm | 0.6299 |
| 57 | 0.0430 | 21 | 0.1590 | 5/16" | 0.3125 | 41/64" | 0.6406 |
| 56 | 0.0465 | 20 | 0.1610 | 8mm | 0.3150 | 16.5mm | 0.6496 |
| 3/64" | 0.0469 | 19 | 0.1660 | O | 0.3160 | 21/32" | 0.6562 |
| 55 | 0.0520 | 18 | 0.1695 | P | 0.3230 | 17mm | 0.6693 |
| 54 | 0.0550 | 11/64" | 0.1719 | 21/64" | 0.3281 | 43/64" | 0.6719 |
| 1.5mm | 0.0591 | 17 | 0.1730 | Q | 0.3320 | 11/16" | 0.6875 |
| 53 | 0.0595 | 16 | 0.1770 | 8.5mm | 0.3346 | 17.5mm | 0.6890 |
| 1/16" | 0.0625 | 4.5mm | 0.1772 | R | 0.3390 | 45/64" | 0.7031 |
| 52 | 0.0635 | 15 | 0.1800 | 11/32" | 0.3438 | 18mm | 0.7087 |
| 51 | 0.0670 | 14 | 0.1820 | S | 0.3480 | 23/32" | 0.7188 |
| 50 | 0.0700 | 13 | 0.1850 | 9mm | 0.3543 | 18.5mm | 0.7283 |
| 49 | 0.0730 | 3/16" | 0.1875 | T | 0.3580 | 47/64" | 0.7344 |
| 48 | 0.0760 | 12 | 0.1890 | 23/64" | 0.3594 | 19mm | 0.7480 |
| 5/64" | 0.0781 | 11 | 0.1910 | U | 0.3680 | 3/4" | 0.7500 |
| 47 | 0.0785 | 10 | 0.1935 | 9.5mm | 0.3740 | 49/64" | 0.7656 |
| 2mm | 0.0787 | 9 | 0.1960 | 3/8" | 0.3750 | 19.5mm | 0.7677 |
| 46 | 0.0810 | 5mm | 0.1969 | V | 0.3770 | 25/32" | 0.7812 |
| 45 | 0.0820 | 8 | 0.1990 | W | 0.3860 | 20mm | 0.7874 |
| 44 | 0.0860 | 7 | 0.2010 | 25/64" | 0.3906 | 51/64" | 0.7969 |
| 43 | 0.0890 | 13/64" | 0.2031 | 10mm | 0.3937 | 20.5mm | 0.8071 |
| 42 | 0.0935 | 6 | 0.2040 | X | 0.3970 | 13/16" | 0.8125 |
| 3/32" | 0.0938 | 5 | 0.2055 | Y | 0.4040 | 21mm | 0.8268 |
| 41 | 0.0960 | 4 | 0.2090 | 13/32" | 0.4062 | 53/64" | 0.8281 |
| 40 | 0.0980 | 3 | 0.2130 | Z | 0.4130 | 27/32" | 0.8438 |
| 2.5mm | 0.0984 | 5.5mm | 0.2165 | 10.5mm | 0.4134 | 21.5mm | 0.8465 |
| 39 | 0.0995 | 7/32" | 0.2188 | 27/64" | 0.4219 | 55/64" | 0.8594 |
| 38 | 0.1015 | 2 | 0.2210 | 11mm | 0.4331 | 22mm | 0.8661 |
| 37 | 0.1040 | 1 | 0.2280 | 7/16" | 0.4375 | 7/8" | 0.8750 |
| 36 | 0.1065 | A | 0.2340 | 11.5mm | 0.4528 | 22.5mm | 0.8858 |
| 7/64" | 0.1094 | 15/64" | 0.2344 | 29/64" | 0.4531 | 57/64" | 0.8906 |
| 35 | 0.1100 | 6mm | 0.2362 | 15/32" | 0.4688 | 23mm | 0.9055 |
| 34 | 0.1110 | B | 0.2380 | 12mm | 0.4724 | 29/32" | 0.9062 |
| 33 | 0.1130 | C | 0.2420 | 31/64" | 0.4844 | 59/64" | 0.9219 |
| 32 | 0.1160 | D | 0.2460 | 12.5mm | 0.4921 | 23.5mm | 0.9252 |
| 3mm | 0.1181 | 1/4" & E | 0.2500 | 1/2" | 0.5000 | 15/16" | 0.9375 |
| 31 | 0.1200 | 6.5mm | 0.2559 | 13mm | 0.5118 | 24mm | 0.9449 |
| 1/8" | 0.1250 | F | 0.2570 | 33/64" | 0.5156 | 61/64" | 0.9531 |
| 30 | 0.1285 | G | 0.2610 | 17/32" | 0.5313 | 24.5mm | 0.9646 |
| 29 | 0.1360 | 17/64" | 0.2656 | 13.5mm | 0.5315 | 31/32" | 0.9688 |
| 3.5mm | 0.1378 | H | 0.2260 | 35/64" | 0.5469 | 25mm | 0.9843 |
| 28 | 0.1405 | I | 0.2720 | 14mm | 0.5512 | 63/64" | 0.9844 |
| 9/64" | 0.1406 | 7mm | 0.2756 | 9/16" | 0.5625 | 1" | 1.0000 |
| 27 | 0.1440 | J | 0.2770 | 14.5mm | 0.5709 | - | - |
