Drill Bit Sizes (Fractional)
Standard fractional inch drill bit sizes as decimal inches and millimeters.
| Size | Decimal | Metric |
|---|---|---|
| 1/16 | 0.0625 | 1.588 |
| 5/64 | 0.078125 | 1.984 |
| 3/32 | 0.09375 | 2.381 |
| 7/64 | 0.109375 | 2.778 |
| 1/8 | 0.125 | 3.175 |
| 9/64 | 0.140625 | 3.572 |
| 5/32 | 0.15625 | 3.969 |
| 11/64 | 0.171875 | 4.366 |
| 3/16 | 0.1875 | 4.763 |
| 13/64 | 0.203125 | 5.159 |
| 7/32 | 0.21875 | 5.556 |
| 15/64 | 0.234375 | 5.953 |
| 1/4 | 0.25 | 6.35 |
| 17/64 | 0.265625 | 6.747 |
| 9/32 | 0.28125 | 7.144 |
| 19/64 | 0.296875 | 7.541 |
| 5/16 | 0.3125 | 7.938 |
| 21/64 | 0.328125 | 8.334 |
| 11/32 | 0.34375 | 8.731 |
| 23/64 | 0.359375 | 9.128 |
| 3/8 | 0.375 | 9.525 |
| 25/64 | 0.390625 | 9.922 |
| 13/32 | 0.40625 | 10.319 |
| 27/64 | 0.421875 | 10.716 |
| 7/16 | 0.4375 | 11.113 |
| 29/64 | 0.453125 | 11.509 |
| 15/32 | 0.46875 | 11.906 |
| 31/64 | 0.484375 | 12.303 |
| 1/2 | 0.5 | 12.7 |
| 9/16 | 0.5625 | 14.288 |
| 5/8 | 0.625 | 15.875 |
| 11/16 | 0.6875 | 17.463 |
| 3/4 | 0.75 | 19.05 |
| 13/16 | 0.8125 | 20.638 |
| 7/8 | 0.875 | 22.225 |
| 15/16 | 0.9375 | 23.813 |
| 1 | 1 | 25.4 |
About this lookup
- What is the most common drill bit set?
- 1/16" through 1/2" in 1/64" increments (29 bits) is the standard set.
- What is a "letter" or "number" drill bit?
- An older system for sizes between fractional sizes (see number-letter lookup).