Nickel (US five cents)
21.21 mm (0.835 in)
Diameter
The US five-cent coin. Diameter: 21.21 mm.
Published
How big is that?
21.21 mm is 25% of a credit card.
Nickel is the 3rd smallest of the 39 Classic objects, and the 3rd smallest of the 109 objects across all three SizeItUp games.
Size comparison
To scale, smallest to largest: Nickel in orange beside the Classic objects nearest in size, in teal.
| Object | Size | vs Nickel |
|---|---|---|
| Dime (US ten cents)The smallest US coin, worth ten cents. | 17.91 mm across | 84% of the size |
| Penny (US one cent)The copper-coloured US cent. Now struck only for collector sets. | 19.05 mm across | 90% of the size |
| Nickel (US five cents) | 21.21 mm across | – |
| US quarterThe 25-cent coin of the United States. | 24.26 mm across | 1.1× bigger |
| LEGO brick (2 x 4)The classic eight-stud building brick. | 31.8 mm long | 1.5× bigger |
In other units
| Millimetres | 21.21 |
|---|---|
| Centimetres | 2.121 |
| Metres | 0.02121 |
| Inches | 0.835 |
| Feet | 0.06959 |
How it's measured
Diameter. US Mint coin specifications.
Sources
- usmint.gov: US Mint coin specifications: nickel diameter 0.835 in., 21.21 mm.
- web.archive.org (supporting): Archived copy of the same page, 21 Oct 2026.
Checked against the source on .
Could you have guessed it by eye?
Nickel is one of the objects in Classic, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.