Decimal Equivalents for Drill Sizes
inch decimal equivalents
metric sizes
fractional sizes
number sizes
letter sizes
metric sizes
fractional sizes
number sizes
letter sizes
Decimal Equivalents from # 80 to 1", .0135" to 1.000"
| Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal | ||||
| 80 | .0135" | 70 | .0280" | 60 | .0400" | 51 | .0670" | 3/32 | .0938" | ||||
| 79 | .0145" | 69 | .0292" | 59 | .0410" | 50 | .0700" | 41 | .0960" | ||||
| 1/64 | .0156" | 68 | .0310" | 58 | .0420" | 49 | .0730" | 40 | .0980" | ||||
| 78 | .0160" | 1/32 | .0313" | 57 | .0430" | 48 | .0760" | 39 | .0995" | ||||
| 77 | .0180" | 67 | .0320" | 56 | .0465" | 5/64 | .0781" | 38 | .1015" | ||||
| 76 | .0200" | 66 | .0330" | 3/64 | .0469" | 47 | .0785" | 37 | .1040" | ||||
| 75 | .0210" | 65 | .0350" | 55 | .0520" | 46 | .0810" | 36 | .1065" | ||||
| 74 | .0225" | 64 | .0360" | 54 | .0550" | 45 | .0820" | 7/64 | .1094" | ||||
| 73 | .0240" | 63 | .0370" | 53 | .0595" | 44 | .0860" | 35 | .1100" | ||||
| 72 | .0250" | 62 | .0380" | 1/16 | .0625" | 43 | .0890" | 34 | .1110" | ||||
| 71 | .0260" | 61 | .0390" | 52 | .0635" | 42 | .0935" | 33 | .1130" |
| Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal | ||||
| 32 | .1160" | 23 | .1540" | 14 | .1820" | 5 | .2055" | E | .2500" | ||||
| 31 | .1200" | 5/32 | .1562" | 13 | .1850" | 4 | .2090" | 1/4 | .2500" | ||||
| 1/8 | .1250" | 22 | .1570" | 3/16 | .1875" | 3 | .2130" | F | .2570" | ||||
| 30 | .1285" | 21 | .1590" | 12 | .1890" | 7/32 | .2188" | G | .2610" | ||||
| 29 | .1360" | 20 | .1610" | 11 | .1910" | 2 | .2210" | 17/64 | .2656" | ||||
| 28 | .1405" | 19 | .1660" | 10 | .1935" | 1 | .2280" | H | .2660" | ||||
| 9/64 | .1406" | 18 | .1695" | 9 | .1960" | A | .2340" | I | .2720" | ||||
| 27 | .1440" | 11/64 | .1719" | 8 | .1990" | 15/64 | .2344" | J | .2770" | ||||
| 26 | .1470" | 17 | .1730" | 7 | .2010" | B | .2380" | K | .2810" | ||||
| 25 | .1495" | 16 | .1770" | 13/64 | .2031" | C | .2420" | 9/32 | .2812" | ||||
| 24 | .1520" | 15 | .1800" | 6 | .2040" | D | .2460" | L | .2900" |
| Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal | Drill | Decimal | ||||
| M | .2950" | 23/64 | .3594" | 29/64 | .4531" | 41/64 | .6406" | 53/64 | .8281" | ||||
| 19/64 | .2969" | U | .3680" | 15/32 | .4688" | 21/32 | .6562" | 27/32 | .8438" | ||||
| N | .3020" | 3/8 | .3750" | 31/64 | .4844" | 43/64 | .6719" | 55/64 | .8594" | ||||
| 5/16 | .3125" | V | .3770" | 1/2 | .5000" | 11/16 | .6875" | 7/8 | .8750" | ||||
| O | .3160" | W | .3860" | 33/64 | .5156" | 45/64 | .7031" | 57/64 | .8906" | ||||
| P | .3230" | 25/64 | .3906" | 17/32 | .5313" | 23/32 | .7188" | 29/32 | .9062" | ||||
| 21/64 | .3281" | X | .3970" | 35/64 | .5469" | 47/64 | .7344" | 59/64 | .9219" | ||||
| Q | .3320" | Y | .4040" | 9/16 | .5625" | 3/4 | .7500" | 15/16 | .9375" | ||||
| R | .3390" | 13/32 | .4062" | 37/64 | .5781" | 49/64 | .7656" | 61/64 | .9531" | ||||
| 11/32 | .3438" | Z | .4130 | 19/32 | .5938" | 25/32 | .7812" | 31/32 | .9688" | ||||
| S | .3480" | 27/64 | .4219" | 39/64 | .6094" | 51/64 | .7969" | 63/64 | .9844" | ||||
| T | .3580" | 7/16 | .4375" | 5/8 | .6250" | 13/16 | .8125" | 1 | 1.000" |
Millimeter Sizes
Decimal Equivalents
| mm | Decimal | mm | Decimal | mm | Decimal | mm | Decimal | mm | Decimal | ||||
| .35 | .0138" | .90 | .0354" | 1.45 | .0571" | 2.00 | .0787" | 2.55 | .1004" | ||||
| .40 | .0157" | .95 | .0374" | 1.50 | .0591" | 2.05 | .0807" | 2.60 | .1024" | ||||
| .45 | .0177" | 1.0 | .0394" | 1.55 | .0610" | 2.10 | .0827" | 2.65 | .1043" | ||||
| .50 | .0197" | 1.05 | .0413" | 1.60 | .0630" | 2.15 | .0846" | 2.70 | .1063" | ||||
| .55 | .0217" | 1.10 | .0433" | 1.65 | .0650" | 2.20 | .0866" | 2.75 | .1083" | ||||
| .60 | .0236" | 1.15 | .0453" | 1.70 | .0669" | 2.25 | .0886'' | 2.80 | .1102" | ||||
| .65 | .0256" | 1.20 | .0472" | 1.75 | .0689" | 2.30 | .0906" | 2.85 | .1142" | ||||
| .70 | .0276" | 1.25 | .0492" | 1.80 | .0709" | 2.35 | .0925" | 2.90 | .1181" | ||||
| .75 | .0295" | 1.30 | .0512" | 1.85 | .0728" | 2.40 | .0945" | 3.00 | .1181" | ||||
| .80 | .0315" | 1.35 | .0531" | 1.90 | .0748" | 2.45 | .0965" | 3.10 | .1220" | ||||
| .85 | .0335" | 1.40 | .0551" | 1.95 | .0768" | 2.50 | .0984" | 3.20 | .1260" |
| mm | Decimal | mm | Decimal | mm | Decimal | mm | Decimal | mm | Decimal | ||||
| 3.25 | .1280" | 4.1 | .1614" | 4.9 | .1929" | 5.75 | .2264" | 6.6 | .2598" | ||||
| 3.30 | .1299" | 4.2 | .1654" | 5 | .1969" | 5.8 | .2283" | 6.7 | .2638" | ||||
| 3.40 | .1339" | 4.25 | .1673" | 5.1 | .2008" | 5.9 | .2323" | 6.75 | .2657" | ||||
| 3.50 | .1378" | 4.3 | .1693" | 5.2 | .2047" | 6 | .2362" | 6.8 | .2677" | ||||
| 3.6 | .1417" | 4.4 | .1732" | 5.25 | .2067" | 6.1 | .2402" | 6.9 | .2717" | ||||
| 3.7 | .1457" | 4.5 | .1772" | 5.3 | .2087" | 6.2 | .2441" | 7 | .2756" | ||||
| 3.75 | .1476" | 4.6 | .1811" | 5.4 | .2126" | 6.25 | .2461" | 7.1 | .2795" | ||||
| 3.8 | .1496" | 4.7 | .1850" | 5.5 | .2165" | 6.3 | .2480" | 7.2 | .2835" | ||||
| 3.9 | .1535" | 4.75 | .1870" | 5.6 | .2205" | 6.4 | .2520" | 7.25 | .2854" | ||||
| 4 | .1575" | 4.8 | .1890" | 5.7 | .2244" | 6.5 | .2559" | 7.3 | .2874" |
| mm | Decimal | mm | Decimal | mm | Decimal | mm | Decimal | mm | Decimal | ||||
| 7.4 | .2913" | 8.25 | .3248" | 9.1 | .3583" | 9.9 | .3898" | 14.5 | .5709" | ||||
| 7.5 | .2953" | 8.3 | .3268" | 9.2 | .3622" | 10 | .3937" | 15 | .5906" | ||||
| 7.6 | .2992" | 8.4 | .3307" | 9.25 | .3642" | 10.5 | .4134" | 15.5 | .6102" | ||||
| 7.7 | .3031" | 8.5 | .3346" | 9.3 | .3661" | 11 | .4331" | 16 | .6229" | ||||
| 7.75 | .3051" | 8.6 | .3386" | 9.4 | .3701" | 11.5 | .4528" | 16.5 | .6496" | ||||
| 7.8 | .3071" | 8.7 | .3425" | 9.5 | .3740" | 12 | .4724" | 17 | .6693" | ||||
| 7.9 | .3110" | 8.75 | .3445" | 9.6 | .3780" | 12.5 | .4921" | 17.5 | .6890" | ||||
| 8 | .3150" | 8.8 | .3465" | 9.7 | .3819" | 13 | .5118" | 18 | .7087" | ||||
| 8.1 | .3189" | 8.9 | .3504" | 9.75 | .3839" | 13.5 | .5315" | 18.5 | .7283" | ||||
| 8.2 | .3228" | 9 | .3543" | 9.8 | .3858" | 14 | .5512" | 19 | .7480" |
| mm | Decimal | mm | Decimal | mm | Decimal | ||
| 19.5 | .7677" | 21.5 | .8465" | 23.5 | .9252" | ||
| 20 | .7874" | 22 | .8661" | 24 | .9449" | ||
| 20.5 | .8071" | 22.5 | .8858" | 24.5 | .9646" | ||
| 21 | .8268" | 23 | .9055" | 25 | .9843" |
| FRACTIONAL DECIMAL EQUIVALENTS | ||||||||||
| 1/64 | 0.015625 | 17/64 | 0.265625 | 33/64 | 0.515625 | 49/64 | 0.765625 | |||
| 1/32 | 0.03125 | 9/32 | 0.28125 | 17/32 | 0.53125 | 25/32 | 0.78125 | |||
| 3/64 | 0.046875 | 19/64 | 0.296875 | 35/64 | 0.546875 | 51/64 | 0.796875 | |||
| 1/16 | 0.0625 | 5/16 | 0.3125 | 9/16 | 0.5625 | 13/16 | 0.8125 | |||
| 5/64 | 0.078125 | 21/64 | 0.328125 | 37/64 | 0.578125 | 53/64 | 0.828125 | |||
| 3/32 | 0.09375 | 11/32 | 0.34375 | 19/32 | 0.59375 | 27/32 | 0.84375 | |||
| 7/64 | 0.109375 | 23/64 | 0.359375 | 39/64 | 0.609375 | 55/64 | 0.859375 | |||
| 1/8 | 0.125 | 3/8 | 0.375 | 5/8 | 0.625 | 7/8 | 0.875 | |||
| 9/64 | 0.140625 | 25/64 | 0.390625 | 41/64 | 0.640625 | 57/64 | 0.890625 | |||
| 5/32 | 0.15625 | 13/32 | 0.40625 | 21/32 | 0.65625 | 29/32 | 0.90625 | |||
| 11/64 | 0.171875 | 27/64 | 0.421875 | 43/64 | 0.671875 | 59/64 | 0.921875 | |||
| 3/16 | 0.1875 | 7/16 | 0.4375 | 11/16 | 0.6875 | 15/16 | 0.9375 | |||
| 13/64 | 0.203125 | 29/64 | 0.453125 | 45/64 | 0.703125 | 61/64 | 0.953125 | |||
| 7/32 | 0.21875 | 15/32 | 0.46875 | 23/32 | 0.71875 | 31/32 | 0.96875 | |||
| 15/64 | 0.234375 | 31/64 | 0.484375 | 47/64 | 0.734375 | 63/64 | 0.984375 | |||
| 1/4 | 0.250 | 1/2 | 0.500 | 3/4 | 0.750 | 1 | 1.000 | |||
| NUMBER DRILL SIZES | |||||||
| No. | Size of No. in Decimals | No. | Size of No. in Decimals | No. | Size of No. in Decimals | No. | Size of No. in Decimals |
| 1 | 0.2280 | 21 | 0.1590 | 41 | 0.0960 | 61 | 0.0390 |
| 2 | 0.2210 | 22 | 0.1570 | 42 | 0.0935 | 62 | 0.0380 |
| 3 | 0.2130 | 23 | 0.1540 | 43 | 0.0890 | 63 | 0.0370 |
| 4 | 0.2090 | 24 | 0.1520 | 44 | 0.0860 | 64 | 0.0360 |
| 5 | 0.2055 | 25 | 0.1495 | 45 | 0.0820 | 65 | 0.0350 |
| 6 | 0.2040 | 26 | 0.1470 | 46 | 0.0810 | 66 | 0.0330 |
| 7 | 0.2010 | 27 | 0.1440 | 47 | 0.0785 | 67 | 0.0320 |
| 8 | 0.1990 | 28 | 0.1405 | 48 | 0.0760 | 68 | 0.0310 |
| 9 | 0.1960 | 29 | 0.1360 | 49 | 0.0730 | 69 | 0.02925 |
| 10 | 0.1935 | 30 | 0.1285 | 50 | 0.0700 | 70 | 0.0280 |
| 11 | 0.1910 | 31 | 0.1200 | 51 | 0.0670 | 71 | 0.0260 |
| 12 | 0.1890 | 32 | 0.1160 | 52 | 0.0635 | 72 | 0.0250 |
| 13 | 0.1850 | 33 | 0.1130 | 53 | 0.0595 | 73 | 0.0240 |
| 14 | 0.1820 | 34 | 0.1110 | 54 | 0.0550 | 74 | 0.0225 |
| 15 | 0.1800 | 35 | 0.1100 | 55 | 0.0520 | 75 | 0.0210 |
| 16 | 0.1770 | 36 | 0.1065 | 56 | 0.0465 | 76 | 0.0200 |
| 17 | 0.1730 | 37 | 0.1040 | 57 | 0.0430 | 77 | 0.0180 |
| 18 | 0.1695 | 38 | 0.1015 | 58 | 0.0420 | 78 | 0.0160 |
| 19 | 0.1660 | 39 | 0.0995 | 59 | 0.0410 | 79 | 0.0145 |
| 20 | 0.1610 | 40 | 0.0980 | 60 | 0.0400 | 80 | 0.0135 |
| LETTER DRILL SIZE | |||
| A | 0.234 | N | 0.302 |
| B | 0.238 | O | 0.316 |
| C | 0.242 | P | 0.323 |
| D | 0.246 | Q | 0.332 |
| E | 0.250 | R | 0.339 |
| F | 0.257 | S | 0.348 |
| G | 0.261 | T | 0.358 |
| H | 0.266 | U | 0.368 |
| I | 0.272 | V | 0.377 |
| J | 0.277 | W | 0.386 |
| K | 0.281 | X | 0.397 |
| L | 0.290 | Y | 0.404 |
| M | 0.295 | Z | 0.413 |
