7/8 inch in decimal and mm
Decimal inches
0.875 in
Millimetres
22.225 mm
From the standard, the international inch, 25.4 mm exactly
The math
- A fraction is its top number divided by its bottom number: 7/8 in = 7 ÷ 8 = 0.875 in.
- An inch is exactly 25.4 mm, so 0.875 × 25.4 = 22.225 mm.
- In feet, divide by 12: 0.875 ÷ 12 = 0.072917 ft. In centimetres, divide the mm by 10: 2.2225 cm.
- The same size in finer steps: 7/8 = 14/16 = 28/32 = 56/64. A tape marked in 16ths, 32nds or 64ths shows it at those marks.
Drills, plywood and lumber at 7/8 in
| Drill | Size | Off by |
|---|---|---|
| 22 mm | 0.8661 in | −0.225 mm |
| 22.5 mm | 0.8858 in | +0.275 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.