Drill Bit Sizes with Drill Chart (2024)

Having the right drill bit sizes on hand for your particular repair or building task is essential for any seasoned carpenter or weekend-DIY’er.

Knowing just what size you need to use for the hole you’re making is also important.

It may not be totally evident at first glance.

Many times, we’re just trying to find out the alternative sizes available if you’re working with metric sizes (measured in millimeters) versus standard or empirical values (our familiar fractional inch variety).

TIP:Check out our full drill charts below for a quick reference to find all drill size equivalents.

Finally, getting the right size drill bit set in your greater tool “chest” will arm you for the various types of projects you’re doing.

We’ll discuss these in detail in this article.

Scroll down if you just need a quick reference using our drill chart.

How Many Drill Bit Sizes Are There?

First things first. If you were to look at the most all encompassing collection of multi-purpose, twist-type bits, how many drill bit sizes would there be?

Well, if you base your answer on how many size holes there are in the world, then there would be infinite amount of bits!

Thankfully, we can narrow it down a a lot to some standard sized holes for bolts and screws as well as for bits.

For example, let’s look at the most common applications:

Everyday home repair and construction projects, hobby, marine, farming, woodworking, metal working, aircraft, arts and crafts, commercial building projects, machinery and more.

You get the point!

For each particular application area, you’re going to just see a few dozen or so relevant drill bit sizes.

Drill Bit Sizes with Drill Chart (1)

In fact, most nice sets include anywhere from 12-30 pieces of standard drill bit sizes. (And much more when you factor in different types of bits).

Using our drill chart that follows below, you’ll get an idea of just how many sizes there are!

Types of Drill Bits

Various bit types exist for a wide variety of applications, and in particular what material you’re drilling into.

For the sake of simplicity, let’s look at a basic multi-purpose set.

One that could serve any of the above mentioned disciplines well.

Say, for example, a typical 29-piece set. In the following drill bit chart are the typical fractional sizes this kind of set would include.

This would generally apply to many drill bit types, such as black oxide, titanium, carbide, high-speed steel and masonry (concrete), to name a few.

Basic, twist-type drill bit sizes (fractional):

  • 1/16″
  • 5/64″
  • 3/32″
  • 7/64″
  • 1/8″
  • 9/64″
  • 5/32″
  • 11/64″
  • 3/16″
  • 13/64″
  • 7/32″
  • 15/64″
  • 1/4″
  • 17/64″
  • 9/32″
  • 19/64″
  • 5/16″
  • 21/64″
  • 11/32″
  • 23/64″
  • 3/8″
  • 25/64″
  • 13/32″
  • 27/64″
  • 7/16″
  • 29/64″
  • 15/32″
  • 31/64″
  • 1/2″

There are indeed larger sets. Specialty fasteners sometimes call for a size that would be considered uncommon.

Sets with even more varying drill bit sizes would include diameters smaller than 1/16″ or larger than 1-1/2″.

In between in these large tiny and large sizes are every equivalent bit size known to “man”, so you always have the exact size needed depending on what you’re project is calling for.

Here would be the standard drill bit sizes for spade bits (13-pieces):

1/4″11/16″1-1/4″
3/8″3/4″1-3/8″
1/2″7/8″1-1/2″
9/16″1″
5/8″1-1/8″

And sizes for step drill bits:

  • Range from 1/8″ to 1-3/8″

If you need drill bit sizes that are larger than 1″, you can often use a spade bit for wood and other soft materials.

To avoid break-outs and chipping, you can stick to bigger round-shank types.

For shank bits, you’ll work with these sizes (values in inches):

1/25/83/47/81
33/6441/6449/6457/641-1/8
17/3221/3225/3229/321-1/4
35/6443/6451/6459/641-3/8
9/1611/1613/1615/161-1/2
37/6445/6453/6461/64
19/3223/3227/3231/32
39/6447/6455/6463/64

How Do You Know What Size Drill Bits You Need?

If you’re an average weekend-warrior, you’ve probably stared at a screw or bolt for a few moments and wondered what size drill bit you would need.

Over time, you get so that you can literally eye-ball it and make an educated guess.

But if you’re looking at a less common drill bit size, you need an aid to help you.

A drill bit size hole card can be very helpful for this. A simple plastic drill chart sheet with perfect round holes and markings on it lets you do a couple of things.

First, you can size screws simply by inserting them into a hole then reading the marking.

You can also size drill bits by pushing them through holes.

This is especially helpful if you can’t read the engraved size markings on the bits.

Of course, you can refer to a screw sizing chart like this one to find out more precisely the exact sizes.

It’s also helpful to find the substitute bit size to cross over between metric and standard measurements.

How to Convert and Find Equivalent Bit Sizes

You can use the drill chart that follows this section to help convert sizes, or you can do the math yourself.

Drill Bit Sizes with Drill Chart (2)

To make things just a little more complicated, not all drill bit sizes are in North American fractional measurements.

The metric system is used to define metric drill bit sizes as well.

If you have this set, or need to match, just use a simple formula to convert from metric to fractional inches, and vice versa:

  • Converting from millimeters into inches: Multiply by 0.039
  • Converting from inches to millimeters: Multiply by 25.4

Matching Screw Sizes

Drill Bit Sizes with Drill Chart (3)

If you’re curious what size drill bit you’ll need for a particular screw size (for pre-drilling pilot holes), use the following drill bit size chart:

Screw Size

  • #1
  • #2
  • #3
  • #4
  • #5
  • #6
  • #7
  • #8
  • #9
  • #10
  • #11
  • #12

Hole to clear screw

  • 5/64
  • 3/32
  • 7/64
  • 1/8
  • 1/8
  • 9/64
  • 5/32
  • 11/64
  • 11/64
  • 3/16
  • 3/16
  • 7/32

You can use the following charts and guides to help determine sizes for various types of screws as well:

  • Machine Screw Size Chart
  • Eye-Bolt Size Chart
  • Lag Screw Size Chart

Drill Bit Size Gauge

Even better is to get yourself a drill bit gauge.

These handy cards can help you in a pinch, and can help you to quickly identify which size bit you’ll need based on the screw or hole size you need to drill out. Get one here!

Drill Bit Sizes with Drill Chart (4)

Super handy bit size gauge

Best of all, they’re pretty inexpensive and will be something to have as part of your DIY toolbox for many years to come.

Drill Size Charts:

As promised, the following are all the drill bit charts you’ll ever need to help you quickly convert all standard drill bit sizes to their matching measurements.

If you’re tapping holes you’re pre-drilling you can check out our tap drill chart for specific size conversions.

Drill Chart for Gauge 47-96 (smallest to largest)

This chart lists the North American drill gauge sizes and converts them to their decimal equivalent in both inches and millimeters for metric sizes.

NOTE: Below these charts is the standard fractional size conversion drill chart.

Gauge Dec. (in.) Dec. (mm) Gauge Dec. (in.) Dec. (mm)
960.00630.16710.0260.66
950.00670.17700.0280.711
940.00710.18690.02920.742
930.00750.191680.0310.787
920.00790.201670.0320.813
910.00830.211660.0330.838
900.00870.221650.0350.889
890.00910.231640.0360.914
880.00950.241630.0370.94
870.010.254620.0380.965
860.01050.267610.0390.991
850.0110.279600.041.016
840.01150.292590.0411.041
830.0120.305580.0421.067
820.01250.318570.0431.092
810.0130.33560.04651.181
800.01350.343550.0521.321
790.01450.368540.0551.397
780.0160.406530.05951.511
770.0180.457520.06351.613
760.020.508510.0671.702
750.0210.533500.071.778
740.02250.572490.0731.854
730.0240.61480.0761.93
720.0250.635470.07851.994

Drill Chart for Gauge 1-46 (smallest to largest)

This chart rounds out the second half of these number gauge sizes down to #1, which is the largest drill bit size.

Gauge Dec. (in.) Dec. (mm) Gauge Dec. (in.) Dec. (mm)
460.0812.057230.1543.912
450.0822.083220.1573.988
440.0862.184210.1594.039
430.0892.261200.1614.089
420.09352.375190.1664.216
410.0962.438180.16954.305
400.0982.489170.1734.394
390.09952.527160.1774.496
380.10152.578150.184.572
370.1042.642140.1824.623
360.10652.705130.1854.699
350.112.794120.1894.801
340.1112.819110.1914.851
330.1132.87100.19354.915
320.1162.94690.1964.978
310.123.04880.1995.055
300.12853.26470.2015.105
290.1363.45460.2045.182
280.14053.56950.20555.22
270.1443.65840.2095.309
260.1473.73430.2135.41
250.14953.79720.2215.613
240.1523.86110.2285.791

Drill Chart for Gauge Letters (smallest to largest)

Download full chart

Letter gauge drill sizes are used primarily in North American with A starting with the smallest size working 26 size increments to Z.

Gauge Dec. (in.) Dec. (mm) Gauge Dec. (in.) Dec. (mm)
A0.2345.944N0.3027.671
B0.2386.045O0.3168.026
C0.2426.147P0.3238.204
D0.2466.248Q0.3328.433
E0.256.35R0.3398.611
F0.2576.528S0.3488.839
G0.2616.629T0.3589.093
H0.2666.756U0.3689.347
I0.2726.909V0.3779.576
J0.2777.036W0.3869.804
K0.2817.137X0.39710.08
L0.297.366Y0.40410.26
M0.2957.493Z0.41310.49

Drill Bit Size Chart: Fractional to Decimal & Metric (Small to Large)

The following drill chart covers the smallest standard drill diameter size of strong>1/64 to 21/32 and gives you the equivalent sizes in both decimal inches and millimeters.

Diam.Dec. (In.)Dec. (mm) Diam.Dec. (In.)Dec. (mm)
1/640.01560.396911/320.34388.7313
1/320.03130.793823/640.35949.1281
3/640.04691.19063/80.3759.525
1/160.06251.587525/640.39069.9219
5/640.07811.984413/320.406310.3188
3/320.09382.381327/640.421910.7156
7/640.10942.77817/160.437511.1125
1/80.1253.17529/640.453111.5094
9/640.14063.571915/320.468811.9063
5/320.15633.968831/640.484412.3031
11/640.17194.36561/20.512.7
3/160.18754.762533/640.515613.0969
13/640.20315.159417/320.531313.4938
7/320.21885.556335/640.546913.8906
15/640.23445.95319/160.562514.2875
1/40.256.3537/640.578114.6844
17/640.26566.746919/320.593815.0813
9/320.28137.143839/640.609415.4781
19/640.29697.54065/80.62515.875
5/160.31257.937541/640.640616.2719
21/640.32818.334421/320.656316.6688

This final drill chart covers the standard bit sizes from 43/64 to 1 27/64.

Diam.Dec. (In.)Dec. (mm) Diam.Dec. (In.)Dec. (mm)
43/640.671917.06561125.4
11/160.687517.462511/641.015625.7969
45/640.703117.859411/321.031326.1938
23/320.718818.256313/641.046926.5906
47/640.734418.653111/161.062526.9875
3/40.7519.0517/641.109428.1781
49/640.765619.446911/81.12528.575
25/320.781319.843815/321.156329.3688
51/640.796920.2406111/641.171929.7656
13/160.812520.637513/161.187530.1625
53/640.828121.0344113/641.203130.5594
27/320.843821.431317/321.218830.9563
55/640.859421.8281115/641.234431.3531
7/80.87522.22519/321.281332.5438
57/640.890622.6219119/641.296932.9406
29/320.906323.018815/161.312533.3375
59/640.921923.4156121/641.328133.7344
15/160.937523.8125111/321.343834.1313
61/640.953124.2094123/641.359434.5281
31/320.968824.6063113/321.406335.7188
63/640.984425.0031127/641.421936.1156

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More About Drill Bit Sets and Sizing

Some other helpful information to help you in your knowledge of drill bit sizes:

Fractional Sizing

Fractional sizing uses whole, half (1/2), quarter (1/4), eighth (1/8), sixteenths (1/16) and sixty-fourths (1/64).

For example, something just above 31/64″ would be a half-inch, and anything above 63/64″ would be a 1-inch drill bit size.

Super Long Bits

Drill Bit Sizes with Drill Chart (6)

Long bit sizes have typical lengths of: 12″ or 18″ overall length. These are handy in situations where you need to drill through thick or multi-layered materials.

Professionals in the electrical industry for example will use these when running wires or cables through finished walls and ceilings.

Other contractors will use masonry bits in their hammer drills to bore through materials such as concrete, stones and bricks.

This is especially useful when creating a hole from the outside of your house to the interior. Lengths of up to 18″ or more may be needed.

Drill Bit Point Angles

The typical sizes of drill bit point angles are 115° or 118° (degrees).

When buying a good set, ensure it contains more than just one of the common (important) size drill bits.

Bits do break as they weaken from usage and high amounts of heat generated from friction.

Drill Bit Sizes with Drill Chart (2024)
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