7 inches is exactly 17.78 centimeters, or 177.8 millimeters. That is the nominal size of a 7-inch vinyl single.
7″ = 17.78 cm
Exact, because 1 inch is defined as exactly 25.4 mm
- Centimeters
- = 17.78 cm
How long is 7 inches?
7 in = 7 × 2.54 cm = 17.78 cm, exactly, because 1 inch is defined as exactly 2.54 cm. In other units, 7 inches is exactly 177.8 mm and 0.1778 m. In feet it is ≈ 0.5833 ft, and in yards it is ≈ 0.1944 yd.
Numbers are hard to picture, so here is 7 inches drawn to scale next to real reference lengths.
Things that are about 7 inches long
Each size below comes from an official rule or a published specification. The note after each one says how close it is to 7 inches. Real objects vary.
A 7-inch vinyl single
A 7-inch record is named for a 7 in (17.78 cm) diameter. Real discs vary a little by pressing, so this is a nominal match.
A new, unsharpened pencil
A standard pencil is about 7.5 in (19.05 cm) long, so 7 inches is 0.5 in shorter.
A US dollar bill
A US bill is 6.14 in long, so 7 inches is 0.86 in (about 2.2 cm) longer.
Two bank cards end to end
A bank card is 85.6 mm long, so two in a row are 171.2 mm (≈ 6.74 in), about 0.26 in shorter than 7 inches.
A 7-inch tablet
Small tablets are sold by their screen diagonal, so a 7-inch tablet screen measures 7 inches corner to corner. The device itself is larger than that.
7 inches to centimeters chart
| Inches (in) | Inches (decimal) | Centimeters (cm) |
|---|---|---|
| 1″ | 1 | 2.54 |
| 2″ | 2 | 5.08 |
| 3″ | 3 | 7.62 |
| 4″ | 4 | 10.16 |
| 5″ | 5 | 12.7 |
| 6″ | 6 | 15.24 |
| 7″ | 7 | 17.78 |
| 8″ | 8 | 20.32 |
| 9″ | 9 | 22.86 |
| 10″ | 10 | 25.4 |
| 11″ | 11 | 27.94 |
| 12″ | 12 | 30.48 |
Frequently asked questions
How many cm is 7 inches?
7 inches is exactly 17.78 cm. Multiply inches by 2.54 to get centimeters.
How many mm is 7 inches?
7 inches is exactly 177.8 mm.
How many feet is 7 inches?
7 inches is about 0.583 feet (7 ÷ 12 ≈ 0.5833 ft).
Is 7 inches the same as 18 cm?
Almost. 18 cm is about 7.09 inches, so 7 inches is 0.22 cm (2.2 mm) shorter than 18 cm.
How can I measure 7 inches without a ruler?
A US dollar bill is 6.14 inches, and a new pencil is about 7.5 inches. Use a ruler or tape when it matters.
How do I convert inches to cm?
Multiply the inches by 2.54. For 7 inches, 7 × 2.54 = 17.78 cm.
