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20 cm is 7.87 inches. On a US tape measure, that is the 7 7⁄8 inch mark, just 3.2 mm short of 8 inches. In other units, 20 cm is 200 mm, 0.2 m or 0.66 feet.
20 cm in inches, feet and millimeters
An inch is exactly 2.54 cm, so divide by 2.54: 20 ÷ 2.54 = 7.8740. Rounded to two decimals, 20 cm = 7.87 in. Tape measures in the US are marked in eighths and sixteenths of an inch: the closest mark is 7 7⁄8 in, only 0.03 mm away.
| Centimeters | Inches | Nearest ⅛ inch | Feet |
|---|---|---|---|
| 18 cm | 7.09 | 7 1⁄8 | 0.591 |
| 19 cm | 7.48 | 7 1⁄2 | 0.623 |
| 19.05 cm | 7.50 | 7 1⁄2 | 0.625 |
| 20 cm | 7.87 | 7 7⁄8 | 0.656 |
| 20.32 cm | 8.00 | 8 | 0.667 |
| 21 cm | 8.27 | 8 1⁄4 | 0.689 |
| 22 cm | 8.66 | 8 5⁄8 | 0.722 |
- 20 cm in feet: 0.656 ft, about two-thirds of a foot.
- 20 cm in millimeters: 200 mm.
- 20 cm in meters: 0.2 m, one fifth of a meter.
- 20 cm in yards: 0.219 yd.
Is 20 cm 8 inches?
Not exactly. 8 inches is 20.32 cm, so 20 cm is 3.2 mm (about ⅛ inch) shorter. In everyday use, the two are treated as the same size: a cake pan sold as “20 cm” in Europe is sold as “8 inch” in the US, and a ring light or a speaker can carry both labels.
For a round pan, the difference in area is about 3%. You can bake an 8-inch recipe in a 20 cm pan without changing anything; the cake will just be a hair taller.
What does 20 cm look like? 7 things, room by room
Here are seven things that measure 20 cm, or very close to it. Each photo is drawn to scale next to the same inch and centimeter ruler, so you can compare them with each other.
In the kitchen
1. A 20 cm Springform Pan
Round cake pans are named by their diameter, measured across the inside of the rim. 20 cm is the classic size for a cheesecake or a sponge in metric recipes, and the closest US size is 8 inches.
The clamp on a springform pan sticks out a little, so leave a couple of extra centimeters when you check that it fits in your oven or a cake box.
On the desk
2. An A5 Notebook
A5 is half of an A4 sheet: 14.8 × 21 cm. The long side is just 1 cm over 20 cm, so an A5 notebook is one of the easiest ways to picture 20 cm.
Hardcover notebooks are a few millimeters larger than the pages inside, which puts the cover at about 21.5 cm tall.
3. A New Pencil
A standard unsharpened pencil is 7½ inches long, which is 19.05 cm. Lay it down and add the width of a fingertip, and you have 20 cm.
Each sharpening takes a few millimeters off, so a pencil that has been used for a while is no longer a good reference.
4. A 20 × 30 cm Print
20 × 30 cm is one of the most common photo and poster sizes in Europe. Its short side is 20 cm (7.87 in) and its long side is 30 cm (11.81 in).
In US shops, the nearest size is 8 × 12 inches, which is a few millimeters larger on both sides. A 20 × 30 cm print in an 8 × 12 frame will show a thin gap, unless the frame has a mat.
Around the house
5. An 8-Inch (20 cm) Ring Light
Small ring lights for desks and phones are sold by the diameter of the ring. The 8-inch size, about 20 cm across, is the common choice for video calls and close-up photos.
The light stand and phone holder add to the overall size; the 8 inches only describes the ring.
6. A Toothbrush
Most adult manual toothbrushes measure 18 to 19 cm from the end of the handle to the tip of the head: just short of 20 cm.
Electric toothbrushes with the brush head attached are usually a little longer, often above 20 cm.
7. A 20 cm Cotton Doll
Plush “cotton dolls” are sold by height, and 20 cm is by far the most popular size: clothes, bags and display boxes are made to fit it.
Before buying an outfit, check whether the seller measures the doll standing, from the top of the head to the feet, and whether hair is included.
20 × 30 cm and other “20 × …” sizes in inches
Frames, prints, cushions and boxes are often listed as “20 × something” centimeters. Here are the common ones converted to inches.
| Size | In inches | Typical use |
|---|---|---|
| 10 × 20 cm | 3.94 × 7.87 in | Small gift box, bookmark-style card |
| 15 × 20 cm | 5.91 × 7.87 in | Close to a US 6 × 8 print |
| 20 × 20 cm | 7.87 × 7.87 in | Square photo, napkin, cushion cover |
| 20 × 25 cm | 7.87 × 9.84 in | Close to an 8 × 10 print, but smaller |
| 20 × 30 cm | 7.87 × 11.81 in | Common photo and poster size in Europe |
| 20 × 40 cm | 7.87 × 15.75 in | Panoramic print |
- Is 20 × 30 cm A4? No. A4 is 21 × 29.7 cm: 1 cm wider and 3 mm shorter.
- Is 20 × 25 cm the same as 8 × 10? Almost. 8 × 10 inches is 20.32 × 25.4 cm, so a 20 × 25 cm print is slightly smaller and fits an 8 × 10 frame with a small margin.
20 cm vs. 30 cm, and 20 cm vs. 20 inches
For lengths, 30 cm is simply half again as long as 20 cm. For round things, such as pizzas, cakes and pans, the gap is much bigger: a 30 cm circle has 2.25 times the area of a 20 cm circle, because the area grows with the square of the diameter.
20 inches is 50.8 cm, more than two and a half times 20 cm. If a size chart, a suitcase or a TV lists “20”, check the unit: 20 cm is the length of a notebook, 20 inches is the height of a carry-on bag.
20 cm next to nearby lengths
| Length | In inches | Everyday example |
|---|---|---|
| 15.24 cm | 6 in | A 6-inch sub |
| 19.05 cm | 7.5 in | A new pencil |
| 20 cm | 7.87 in | A 20 cm cake pan |
| 20.32 cm | 8 in | An 8 × 8 baking pan |
| 21 cm | 8.27 in | A5 paper, long side; A4 paper, short side |
| 21.59 cm | 8.5 in | US Letter paper, short side |
How to measure 20 cm without a ruler
- A sheet of A4 paper: the short side is 21 cm, so 20 cm is 1 cm less.
- US Letter paper: the short side is 8.5 inches (21.59 cm); fold back a strip of about 1.6 cm.
- A new pencil: 19.05 cm, plus about 1 cm.
- A tape measure: stop at 7 7⁄8 inches, or read 20 on the metric scale if your tape has one.
More sizes to compare
- What 6 inches looks like: 15.24 cm, from a 6-inch sub to 6 inches of snow
- What 8 inches looks like: 20.32 cm, and why an “8-inch” block is 7⅝ inches
- What 9 inches looks like: 22.86 cm, from a pie dish to a paint roller
- What 10 inches looks like: 25.4 cm, from a saw blade to a 10-inch rough-in toilet
- CM to inches converter: type any length in cm, with a 1–100 cm chart
FAQs
20 cm is 7.87 inches, or 7 7⁄8 inches on a tape measure.
Close, but not quite: 8 inches is 20.32 cm, so 20 cm is 3.2 mm shorter. Pans and lights sold as 20 cm and 8 inches are used interchangeably.
20 cm is 0.656 feet, about two-thirds of a foot.
20 × 30 cm is 7.87 × 11.81 inches, close to an 8 × 12 print.
20 × 20 cm is 7.87 × 7.87 inches, just under 8 × 8 inches.
20 cm is 200 mm, since 1 cm is 10 mm.
An A5 notebook (21 cm), a new pencil (19 cm), a 20 cm cake pan and an 8-inch ring light are all about 20 cm.
To convert any other length, use the cm to inches converter; for a size just above this one, see what 8 inches looks like.