12 mm is about 0.472 inches, or about 15/32 inch (slightly more). It is exactly 1.2 cm. Divide millimeters by 25.4, because 1 inch is defined as exactly 25.4 mm.
12 mm ≈ 15/32″
Slightly more than 15/32″ (by 0.09 mm) · ≈ 0.472 in
- Inches
- ≈ 0.4724 in
- Nearest 1/16″
- 1/2″ 12 mm is 0.7 mm shorter
- Nearest 1/32″
- 15/32″ 12 mm is 0.09 mm longer
- Nearest 1/64″
- 15/32″ 12 mm is 0.09 mm longer
How big is 12 mm?
12 mm = 12 ÷ 25.4 in ≈ 0.47244 in. On a tape measure that is 15/32 in (0.4688 in, 11.906 mm), and 12 mm is longer than that by about 0.09 mm. In other metric units, 12 mm is exactly 1.2 cm and exactly 0.012 m.
Compared with common fractions: 15/32 in is 11.906 mm, so 12 mm is about 0.09 mm more; 1/2 in is 12.7 mm, so 12 mm is 0.7 mm less.
Things that are about 12 mm
These are nominal sizes. Real parts vary a little with the maker, so check the part when fit matters.
An M12 bolt or screw
The “M12” label means a thread diameter of 12 mm, about 0.47 of an inch.
A 12 mm drill bit
A standard metric bit size. The closest fraction bit, 15/32 in, drills a hole about 0.09 mm smaller; a 1/2 in bit drills one 0.7 mm larger.
12 mm panel board
Plywood, MDF and similar boards are sold in 12 mm thickness. In inch sizes that sits just under the nominal 1/2 in (12.7 mm).
Half an inch
1/2 in is exactly 12.7 mm, so it is 0.7 mm longer than 12 mm. People often swap the two when buying parts.
An AAA battery (width)
An AAA cell is up to 10.5 mm in diameter, so it is about 1.5 mm narrower than 12 mm.
Nearby millimeter sizes
Decimals are rounded to 3 places. In the fraction columns, + means the value is slightly longer than the fraction, − slightly shorter, and = exact.
| Millimeters (mm) | Inches (decimal) | Nearest 1/16″ | Nearest 1/32″ |
|---|---|---|---|
| 7 mm | 0.276 | 1/4″ + | 9/32″ − |
| 8 mm | 0.315 | 5/16″ + | 5/16″ + |
| 9 mm | 0.354 | 3/8″ − | 11/32″ + |
| 10 mm | 0.394 | 3/8″ + | 13/32″ − |
| 11 mm | 0.433 | 7/16″ − | 7/16″ − |
| 12 mm | 0.472 | 1/2″ − | 15/32″ + |
| 13 mm | 0.512 | 1/2″ + | 1/2″ + |
| 14 mm | 0.551 | 9/16″ − | 9/16″ − |
| 15 mm | 0.591 | 9/16″ + | 19/32″ − |
| 16 mm | 0.63 | 5/8″ + | 5/8″ + |
| 17 mm | 0.669 | 11/16″ − | 21/32″ + |
Frequently asked questions
How many inches is 12 mm?
12 mm is about 0.472 inches (0.4724 in), or about 15/32 inch, slightly more.
What is 12 mm as a fraction of an inch?
About 15/32 inch. 12 mm is 0.4724 in and 15/32 in is 0.46875 in, so 12 mm is slightly more.
Is 12 mm the same as 1/2 inch?
No. 1/2 inch is 12.7 mm, so 12 mm is 0.7 mm smaller. That gap matters for bolts, tubes and drill bits.
Can I use a 1/2 inch drill bit for a 12 mm hole?
The hole will be 0.7 mm larger than 12 mm, which is loose for a 12 mm bolt. Use a 12 mm bit, or a 15/32 inch bit (11.906 mm) if you want a tight fit.
How many cm is 12 mm?
12 mm is exactly 1.2 cm, because 1 cm is 10 mm.
How do I convert mm to inches?
Divide the millimeters by 25.4. For 12 mm, 12 ÷ 25.4 ≈ 0.472 inches.