3/4 inch in decimal and mm
Decimal inches
0.75 in
Millimetres
19.05 mm
From the standard, the international inch, 25.4 mm exactly
The math
- A fraction is its top number divided by its bottom number: 3/4 in = 3 ÷ 4 = 0.75 in.
- An inch is exactly 25.4 mm, so 0.75 × 25.4 = 19.05 mm, or 19.050 mm to three places.
- In feet, divide by 12: 0.75 ÷ 12 = 0.0625 ft. In centimetres, divide the mm by 10: 1.905 cm.
- The same size in finer steps: 3/4 = 6/8 = 12/16 = 24/32 = 48/64. A tape marked in 16ths, 32nds or 64ths shows it at those marks.
Drills, plywood and lumber at 3/4 in
- 3/4 in drill bit
- Plywood, Performance Category 3/4
- Baltic birch sold as 3/4 (18 mm)
- 3/4 in rough hardwood
- 1x lumber, dressed dry
| Drill | Size | Off by |
|---|---|---|
| 19 mm | 0.748 in | −0.05 mm |
| 19.5 mm | 0.7677 in | +0.45 mm |
Every drill is on the drill bit size chart.
Bits of this size
Sizes either side
Every size is on the fraction to decimal chart; any other size goes in the fraction to decimal calculator.