1-5/8 inch in decimal and mm
Decimal inches
1.625 in
Millimetres
41.275 mm
From the standard, the international inch, 25.4 mm exactly
The math
- A fraction is its top number divided by its bottom number: 1-5/8 in = 1 + 5 ÷ 8 = 1.625 in.
- An inch is exactly 25.4 mm, so 1.625 × 25.4 = 41.275 mm.
- In feet, divide by 12: 1.625 ÷ 12 = 0.135417 ft. In centimetres, divide the mm by 10: 4.1275 cm.
- The same size in finer steps: 1-5/8 = 1-10/16 = 1-20/32 = 1-40/64. A tape marked in 16ths, 32nds or 64ths shows it at those marks.
Drills, plywood and lumber at 1-5/8 in
No drill, plywood or lumber on our charts is exactly 1-5/8 in. The nearest drills are below.
| Drill | Size | Off by |
|---|---|---|
| 1 in | 1 in | −0.625 in |
| 25 mm | 0.9843 in | −16.275 mm |
Every drill is on the drill bit size chart.
Bits of this size
Sizes either side
| Fraction | Decimal | mm |
|---|---|---|
| 1-9/16 in | 1.5625 in | 39.688 mm |
| 1-11/16 in | 1.6875 in | 42.863 mm |
Every size is on the fraction to decimal chart; any other size goes in the fraction to decimal calculator.