- Fractions, Numbers, Letters, Decimals and Metric Equivalents -
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Fraction/|	   |	    |Fraction/|	        |        |Fraction/|	     |
 Number/ | Decimal |   MM   | Number/ | Decimal |   MM   | Number/ | Decimal |   MM
 Letter  |	   |	    | Letter  |	        |        | Letter  |	     |
----------------------------+----------------------------+----------------------------
  1/64"  =  .0156" =   .396 |  #20    =  .161"  =  4.089 |  T      =  .358"  =  9.093
  1/32"  =  .0312" =   .795 |  #19    =  .166"  =  4.216 | 23/64"  =  .3594" =  9.129
  #60    =  .040"  =  1.016 |  #18    =  .1659" =  4.214 |  U      =  .368"  =  9.347
  #59    =  .041"  =  1.041 | 11/64"  =  .1718" =  4.366 |  3/8"   =  .375"  =  9.525
  #58    =  .042"  =  1.067 |  #17    =  .173"  =  4.394 |  V      =  .377"  =  9.576
  #57    =  .043"  =  1.092 |  #16    =  .177"  =  4.496 |  W      =  .386"  =  9.804
  #56    =  .043"  =  1.092 |  #15    =  .180"  =  4.572 | 25/64"  =  .3906" =  9.921
  #55    =  .0465" =  1.181 |  #14    =  .182"  =  4.623 |  X      =  .397"  = 10.084
  3/64"  =  .0468" =  1.191 |  #13    =  .185"  =  4.699 |  Y      =  .404"  = 10.262
  #55    =  .052"  =  1.321 |  3/16"  =  .1875" =  4.763 | 13/32"  =  .4063" = 10.320
  #54    =  .055"  =  1.397 |  #12    =  .189"  =  4.801 |  Z      =  .413"  = 10.490
  #53    =  .0595" =  1.511 |  #11    =  .191"  =  4.851 | 27/64"  =  .4219" = 10.716
  1/16"  =  .0625" =  1.588 |  #10    =  .1935" =  4.915 |  7/16"  =  .4375" = 11.113
  #52    =  .0635" =  1.613 |  #9     =  .196"  =  4.978 | 29/64"  =  .4531" = 11.509
  #51    =  .067"  =  1.701 |  #8     =  .199"  =  5.055 | 15/32"  =  .46509 = 11.318
  #51    =  .067"  =  1.701 |  #8     =  .199"  =  5.055 | 15/32"  =  .4688" = 11.908
  #50    =  .070"  =  1.778 |  #7     =  .201"  =  5.105 | 31/64"  =  .4844" = 12.304
  #49    =  .073"  =  1.854 | 13/64"  =  .2031" =  5.159 |  1/2"   =  .500"  = 12.700
  #48    =  .076"  =  1.930 |  #6     =  .204"  =  5.182 | 33/64"  =  .5156" = 13.096
  5/64"  =  .0781" =  1.984 |  #5     =  .2055" =  5.220 | 17/32"  =  .5312" = 13.495
  #47    =  .0785" =  1.994 |  #4     =  .209"  =  5.309 | 35/64"  =  .5469" = 13.891
  #46    =  .081"  =  2.060 |  #3     =  .213"  =  5.410 |  9/16"  =  .5625" = 14.288
  #45    =  .082"  =  2.083 |  7/32"  =  .2188" =  5.558 | 37/64"  =  .5781" = 14.684
  #44    =  .086"  =  2.184 |  #2     =  .221"  =  5.613 | 19/32"  =  .5938" = 15.083
  #43    =  .089"  =  2.260 |  #1     =  .228"  =  5.791 | 39/64"  =  .6094" = 15.479
  #42    =  .0935" =  2.375 |  A      =  .234"  =  5.943 |  5/8"   =  .625"  = 15.875
  3/32"  =  .0937" =  2.383 | 15/64"  =  .2344" =  5.954 | 41/64"  =  .6406" = 16.271
  #41    =  .096"  =  2.438 |  B      =  .238"  =  6.045 | 21/32"  =  .6563" = 16.670
  #40    =  .098"  =  2.489 |  C      =  .242"  =  6.147 | 43/64"  =  .6719" = 17.066
  #39    =  .0995" =  2.527 |  D      =  .246"  =  6.248 | 11/16"  =  .6875" = 17.463
  #38    =  .1015" =  2.578 |  1/4"   =  .250"  =  6.350 | 45/64"  =  .7031" = 17.859
  #37    =  .104"  =  2.642 |  E      =  .250"  =  6.350 | 23/32"  =  .7188" = 18.254
  #36    =  .1065  =  2.705 |  F      =  .257"  =  6.528 | 47/64"  =  .7344" = 18.654
  7/64"  =  .1094" =  2.779 |  G      =  .261"  =  6.629 |  3/4"   =  .750"  = 19.050
  #35    =  .110"  =  2.794 | 17/64"  =  .2656" =  6.746 | 49/64"  =  .7656" = 19.446
  #34    =  .111"  =  2.819 |  H      =  .266"  =  6.756 | 25/32"  =  .7813" = 19.845
  #33    =  .113"  =  2.870 |  I      =  .272"  =  6.909 | 51/64"  =  .7969" = 20.241
  #32    =  .116"  =  2.946 |  J      =  .277"  =  7.036 | 13/16"  =  .8125" = 20.638
  #31    =  .120"  =  3.048 |  K      =  .281"  =  7.137 | 53/64"  =  .8282" = 21.034
  1/8"   =  .125"  =  3.175 |  9/32"  =  .2813" =  7.145 | 27/32"  =  .8438" = 21.433
  #30    =  .1285" =  3.195 |  L      =  .290"  =  7.366 | 55/64"  =  .8594" = 21.821
  #29    =  .136"  =  3.454 |  M      =  .295"  =  7.493 |  7/8"   =  .875"  = 22.225
  #28    =  .1405" =  3.569 | 19/64"  =  .2969" =  7.541 | 57/64"  =  .8906" = 22.621
  9/64"  =  .1406" =  3.571 |  N      =  .302"  =  7.671 | 29/32"  =  .9063" = 23.020
  #27    =  .144"  =  3.658 |  5/16"  =  .3125" =  7.938 | 59/64"  =  .9219" = 23.416
  #26    =  .147"  =  3.734 |  O      =  .316"  =  8.026 | 15/16"  =  .9375" = 23.813
  #25    =  .1495" =  3.797 |  P      =  .323"  =  8.204 | 61/64"  =  .9532" = 24.209
  #24    =  .152"  =  3.861 | 21/64"  =  .3281" =  8.334 | 31/32"  =  .9688" = 24.608
  #23    =  .154"  =  3.912 |  Q      =  .332"  =  8.433 | 63/64"  =  .9844" = 25.004
  5/32"  =  .1563" =  3.970 |  R      =  .339"  =  8.611 |     1"  = 1.000"  = 25.400
  #22    =  .157"  =  3.988 | 11/32"  =  .3438" =  8.733 |
  #21    =  .159"  =  4.039 |  S      =  .348"  =  8.839 |

NOTE: There's three different types drill bits - fraction, number (wire) and letter. Actually, there's four, including the metric ones. Use the one that's closest according to the hole you need to drill.
© 1996-Present. Designed and maintained by Brian Miller.