4 inch in decimal and mm
Decimal inches
4 in
Millimetres
101.6 mm
From the standard, the international inch, 25.4 mm exactly
The math
- A fraction is its top number divided by its bottom number: 4 in = 4 in = 4 in.
- An inch is exactly 25.4 mm, so 4 × 25.4 = 101.6 mm, or 101.600 mm to three places.
- In feet, divide by 12: 4 ÷ 12 = 0.333333 ft. In centimetres, divide the mm by 10: 10.16 cm.
Drills, plywood and lumber at 4 in
| Drill | Size | Off by |
|---|---|---|
| 1 in | 1 in | −3 in |
| 25 mm | 0.9843 in | −76.6 mm |
Every drill is on the drill bit size chart.
Bits of this size
Sizes either side
| Fraction | Decimal | mm |
|---|---|---|
| 3-3/4 in | 3.75 in | 95.250 mm |
Every size is on the fraction to decimal chart; any other size goes in the fraction to decimal calculator.