Find a size
Pick a sizing system, then pick the size.
Interactive dimensional reference
Look up the decimal-inch and metric equivalent for any fractional, number (wire gauge), letter, or metric twist drill size — and instantly see the closest match in the other three systems. All sizes follow ANSI/ASME B94.11M.
Pick a sizing system, then pick the size.
Values update instantly from the selected size, with the closest match in each other system.
Shop jobber-length twist drills and drill mills sized to the exact fractional, number, letter, or metric diameter you just looked up.
Complete reference
1/64" through 1", in 1/64" increments.
| Fraction | Decimal (in) | Millimeters |
|---|
Complete reference
#80 (smallest) through #1 (largest).
| Drill No. | Decimal (in) | Millimeters |
|---|
Complete reference
A (smallest) through Z (largest).
| Letter | Decimal (in) | Millimeters |
|---|
Complete reference
0.5mm through 25mm, standard increments.
| Metric | Decimal (in) | Millimeters |
|---|
Reference: ANSI/ASME B94.11M twist drill size standard (fractional, number/wire-gauge, letter, and metric drill diameters). Values cross-checked against LittleMachineShop.com number and letter drill size charts and Wikipedia's ANSI B94.11M decimal-equivalent tables.