If you’ve ever wondered how long 20 cm is, you’re not alone. Centimeters show up constantly in recipes, packaging, and school assignments, but most people don’t carry a mental ruler with them.
The good news is that 20 cm is one of the easiest lengths to picture once you connect it to a few familiar objects.
In plain terms, 20 centimeters is a medium-small length noticeably longer than a smartphone but shorter than a standard sheet of paper’s long edge. It’s roughly the length of a dinner fork, a small paperback book, or a wooden cooking spoon.
This guide covers exact conversions for 20 cm into inches, millimeters, meters, and feet, plus 16 everyday objects close to this size, tips for estimating it without a ruler, and answers to common questions about the measurement.
Quick Conversion / Measurement Reference
Twenty centimeters is a metric length that converts to the following commonly used units:
| UNIT | VALUE |
| Centimeters | 20 cm |
| Millimeters | 200 mm |
| Meters | 0.2 m |
| Inches | 7.87 in |
| Feet | 0.656 ft |
In short, 20 cm equals almost 8 inches, or a little over two-thirds of a foot It’s exactly one-fifth of a meter, which makes it an easy fraction to remember when converting between metric units.
Quick Reference Table
Here’s a snapshot of common items that are close to 20 cm, so you can jump straight to a comparison that makes sense to you.
| ITEM | APPROXIMATE LENGTH / SIZE | HOW CLOSE TO 20 CM |
| 20 cm personal pizza | 20 cm diameter | Exact |
| Standard house brick (length) | 21.5 cm | Very close |
| Chef’s knife blade (8-inch) | 20.3 cm | Very close |
| iPad mini–style tablet (diagonal) | 20 cm | Exact |
| Wooden cooking spoon | 19–21 cm | Very close |
| Unsharpened HB pencil | 19 cm | Close |
| Standard DL envelope (length) | 22 cm | Close |
| Trade paperback novel (height) | 20.3 cm | Very close |
What Does 20 cm Look Like?
Picture a dinner fork laid next to a smartphone 20 cm sits right around that range, a little longer than most phones and shorter than a standard 30 cm ruler.
Spreading your thumb and pinky as wide as they’ll go (“hand span”) also gets close to 20 cm for most adults a useful body-based reference when you don’t have a tape measure handy.
A horizontal ruler graphic marked from 0–20 cm with small icons (pencil, fork, smartphone, pizza slice) placed along it to show scale. Suggested Image Alt Text: “20 cm size comparison ruler with everyday objects”
How Long Is 20 cm in Inches, Millimeters, Feet, and Other Units?
Converting 20 cm into other units is straightforward once you know the base conversion factor: 1 cm = 0.3937 inches.
- 20 cm in inches: 7.87 in (often rounded to 8 in)
- 20 cm in millimeters: 200 mm
- 20 cm in meters: 0.2 m
- 20 cm in feet: 0.656 ft
- 20 cm in yards: 0.219 yd
Because 20 cm is almost exactly 8 inches, many people round it that way in casual conversation — though true 8 inches is 20.32 cm, a small but real difference if precision matters, as in woodworking or sewing.
16 Everyday Objects That Are About 20 cm Long
Numbers on a page are hard to visualize, so here are 16 real-world objects that hover around the 20 cm mark. Some are exact matches; others are close enough to give a reliable mental image.
1. A Folded Newspaper for a Quick 20 cm Comparison
A newspaper folded for a newsstand rack typically measures around 20–22 cm across the folded edge, depending on the publication a handy comparison for anyone who’s handled a folded paper.
2. A Standard Unsharpened HB Pencil
A brand-new, unsharpened HB pencil is usually about 19 cm long, just shy of 20 cm. Sharpening shortens it over time, so a fresh pencil straight out of the box is your best reference.
Related Post: What is 30 cm in inches? Exact Answer, Conversion Formula & 12 Examples
3. A Men’s Dress Shoe Around Size 8 UK or 42 EU
Certain structural sections of a men’s dress shoe in this size rather than its full heel-to-toe length, which runs a bit longer land in the neighborhood of 20 cm.
4. The Typical Width of a Paperback Novel
Standard trade paperbacks are often printed at a trim size of about 12.7 cm by 20.3 cm, so the longer edge of a typical paperback is remarkably close to 20 cm.
5. A Wooden Cooking Spoon Around 20 cm Long
Smaller wooden cooking spoons, especially ones for children’s kitchen sets or compact drawers, commonly measure 19–21 cm from tip to handle end.
6. A Small Compact Tablet With a Similar Screen Size
Compact tablets with roughly 7.9-inch diagonal screens measure almost exactly 20 cm corner to corner one of the most precise comparisons on this list.
7. A Standard DL Envelope for a Simple Size Reference
A DL envelope, the common size for business letters, measures 11 cm by 22 cm its longer edge is a close, easy-to-check comparison.
8. A Newborn Baby’s Foot as a Rough 20 cm Comparison
A newborn’s foot alone is much smaller than 20 cm, but the heel-to-knee length often falls in this general range, which is why parenting size charts sometimes use it as a loose comparison point.
9. A Tall 500 ml Can With a Similar Height
Slim style beverage cans and bottles, taller and narrower than a standard soda can, often come close to 20 cm in height.
10. A 20 cm Personal Pizza and Its Actual Diameter
A “personal size” pizza is frequently made to an exact 20 cm diameter one of the few genuinely precise, everyday matches for this measurement.
11. A Hardback Children’s Book Around This Size
Many hardback picture books and storybooks are printed at heights close to 20–23 cm, giving young readers another familiar reference.
12. A Standard House Brick Measured Along Its Length
A standard UK house brick measures 21.5 cm along its longest edge a solid, tangible way to picture 20 cm.
13. A Large Smartphone That Measures Close to 20 cm
The largest “plus” or “ultra” smartphones approach the high teens in height and get reasonably close to 20 cm, especially with a protective case.
14. A Medium Kitchen Knife With a Similar Overall Length
An 8-inch chef’s knife blade measures exactly 20.3 cm, making it one of the more precise comparisons on this list.
15. A Small Notebook That Is Close to 20 cm
A5-sized notebooks, a popular choice for journaling, measure about 21 cm by 14.8 cm, so the longer edge sits right around 20 cm.
16. Common Household Items You Can Use to Estimate 20 cm
A few more items close to 20 cm: a hairbrush handle to bristle tip, a TV remote control, a rolled-up pair of socks, a small cutting board, or a hand-sized mirror.
How to Measure 20 cm Without a Ruler
When you don’t have a ruler or tape measure nearby, everyday objects and body-based estimates can get you remarkably close to 20 cm.
Practical Comparison Table:
| REFERENCE OBJECT | APPROXIMATE SIZE | HOW IT HELPS |
| Adult hand span (thumb to pinky) | 18–22 cm | Quick body-based estimate, varies by person |
| Dollar bill (long edge) | 15.6 cm | Slightly shorter, useful as a lower bound |
| Standard smartphone | 14–17 cm | Slightly shorter, good for visual comparison |
| Two stacked credit cards (long edge) | 17 cm | Close, useful when stacked with a small buffer |
These comparisons are approximate rather than exact, since hand size and product dimensions vary. For anything requiring precision, an actual measuring tool is always the better choice.
Related Post: Coke Can Size: Complete Measurements, Dimensions, Height, and Diameter Guide
How Big Is a 20 cm Pizza? Understanding Pizza Diameter
A 20 cm pizza is generally classified as a “personal” or single-serving size, smaller than a standard 30 cm medium pizza. At 20 cm across, the surface area is roughly 314 square centimeters enough for a modest lunch, but smaller than pizzas typically shared between two or more people.
20 cm Compared With Common Objects Around Your Home
Walking around a typical home, 20 cm shows up more often than people expect: a dinner plate’s radius, the height of a small houseplant pot, or the length of a TV remote. Once you start noticing it, 20 cm becomes an easy length to spot without reaching for a measuring tape.
What Does 20 cm Look Like in Real Life?
In real-life terms, 20 cm is a length you can comfortably hold in one hand longer than a pen, shorter than a school ruler, and close to a dinner fork or a small kitchen utensil.
20 cm Compared With Common Household Objects
A few more quick comparisons: a bar of soap laid end to end with a spare inch, a stack of about four smartphones, or a rolled bath towel’s width when folded in thirds.
How to Estimate 20 cm Without a Ruler
For a fast estimate, use your hand span, a dollar bill plus a thumb’s width, or two stacked credit cards with a small gap.
Is 20 cm Considered Long or Short?
Context matters. For a pencil or a kitchen utensil, 20 cm is fairly typical. For a smartphone or a shoe, it’s on the large side. For a room or a piece of furniture, it’s quite short. In everyday terms, 20 cm sits in the “small to medium” range for handheld objects.
20 cm vs 10 cm, 15 cm, and 30 cm: Size Comparison
Seeing 20 cm next to nearby measurements helps put its scale in perspective.
| MEASUREMENT | APPROXIMATE VALUE | DIFFERENCE |
| 10 cm | 3.94 in | Half the length of 20 cm |
| 15 cm | 5.91 in | 5 cm shorter than 20 cm |
| 20 cm | 7.87 in | Reference point |
| 30 cm | 11.81 in | 10 cm longer than 20 cm (a standard ruler) |
Twenty centimeters is exactly double 10 cm and two-thirds of a standard 30 cm ruler — useful mental shortcuts for quick estimates.
Why 20 cm Is a Useful Measurement for Everyday Objects
Twenty centimeters lands in a genuinely practical range: big enough to be useful (a knife blade, a book, a food portion) but small enough to be portable and easy to store.
That’s likely why so many everyday objects from pencils to pizzas to paperbacks cluster naturally around this length.
Frequently Asked Questions About How Long Is 20 cm
How long is 20 cm in inches?
20 cm is approximately 7.87 inches, often rounded to 8 inches in everyday conversation.
What everyday object is exactly 20 cm?
A personal-size pizza is commonly made to an exact 20 cm diameter, making it one of the most precise real-world matches for this measurement.
Is 20 cm bigger than a smartphone?
Yes, most smartphones measure between 14 and 17 cm in height, so 20 cm is noticeably longer than a typical phone.
How many millimeters are in 20 cm?
20 cm equals 200 mm, since there are 10 mm in every centimeter.
Is 20 cm the same as 8 inches?
Not exactly 20 cm is 7.87 inches, while true 8 inches equals 20.32 cm. They’re close enough for casual use but not identical.
What household item can I use to estimate 20 cm?
An adult hand span (thumb to pinky stretched wide) or a standard dinner fork are both reliable, readily available references for roughly 20 cm.
How does 20 cm compare to a standard ruler?
A standard ruler is 30 cm long, so 20 cm covers about two-thirds of its full length.
Is 20 cm a common size for books?
Yes, many paperback novels and children’s hardbacks have a height close to 20 cm, making books one of the most reliable comparisons for this measurement.
Conclusion
Twenty centimeters about 7.87 inches, 200 millimeters, or 0.2 meters is a length that shows up constantly in daily life, from the diameter of a personal pizza to the blade of a kitchen knife to the height of a paperback book.
Whether you’re converting units for a recipe or general curiosity, the figures above give a precise answer, while the everyday comparisons make it easy to picture without any tools.
The simplest way to remember 20 cm: picture a personal pizza or an 8-inch chef’s knife blade both are near-exact matches.