18 cm at a glance
- Inches
- 7.0866 in
- Nearest 1/16 in
- 7 1/16 in
- Nearest 1/8 in
- 7 1/8 in
- Feet & inches
- 7.09 in (under 1 ft)
- Millimeters
- 180 mm
- Meters
- 0.18 m
How to convert 18 cm to inches
18 ÷ 2.54 = 7.086614 in
The inch has been defined as exactly 2.54 cm since 1959, so dividing by 2.54 is exact; the long decimal is just what that division produces. Multiplying by 0.3937 gives the same answer to four places.
Quick estimate
Multiply by 4 and divide by 10: 18 × 0.4 = 7.2 in. That overshoots by 0.11 in (about 1.6%) — fine for a rough check.
Reading 18 cm on an inch tape measure
US rulers mark fractions of an inch rather than decimals. Here is 7.0866 in rounded to each common mark, with the error that rounding introduces:
| Precision | Tape-measure reading | Error |
|---|---|---|
| 1/2 in | 7 in | −2.20 mm |
| 1/4 in | 7 in | −2.20 mm |
| 1/8 in | 7 1/8 in | +0.98 mm |
| 1/16 in | 7 1/16 in | −0.61 mm |
| 1/32 in | 7 3/32 in | +0.18 mm |
Things about 18 cm long
- About the same as the diameter of a 7-inch vinyl single, 17.78 cm (7 in).
- 6% shorter than a new, unsharpened pencil (about 7½ in), 19.05 cm (7.5 in).
- 15% longer than the length of a US dollar bill, 15.6 cm (6.14 in).
- Photo sizes. 13 × 18 cm prints match the 5 × 7 in size (12.7 × 17.78 cm) closely.
Centimeters near 18 cm
| Centimeters | Inches | Nearest 1/16 in |
|---|---|---|
| 13 cm | 5.1181 in | 5 1/8 in |
| 14 cm | 5.5118 in | 5 1/2 in |
| 15 cm | 5.9055 in | 5 7/8 in |
| 16 cm | 6.2992 in | 6 5/16 in |
| 17 cm | 6.6929 in | 6 11/16 in |
| 18 cm | 7.0866 in | 7 1/16 in |
| 19 cm | 7.4803 in | 7 1/2 in |
| 20 cm | 7.874 in | 7 7/8 in |
| 21 cm | 8.2677 in | 8 1/4 in |
| 22 cm | 8.6614 in | 8 11/16 in |
| 23 cm | 9.0551 in | 9 1/16 in |
Going the other way: 7 inches to cm is exactly 17.78 cm.
Frequently asked questions
How many inches is 18 cm?
18 cm is 7.09 inches (7.0866 to four places), found by dividing 18 by 2.54.
What is 18 cm in inches as a fraction?
To the nearest sixteenth, 18 cm is 7 1/16 in; to the nearest eighth it is 7 1/8 in.
Is 18 cm bigger than an inch?
Yes. 18 cm is 7.09 in, because one inch is only 2.54 cm.
How do I convert 18 cm to inches without a calculator?
Multiply by 0.4 for a quick estimate (7.2 in), then shave off about 1.6% to get close to the exact 7.09 in.