
It's about seventenths as big as a Dime
In other words, 181 square millimeters is 0.71850 times the size of a Dime, and the size of a Dime is 1.3920 times that amount.
(United States tencent coin) (a.k.a. Roosevelt dime)The dime, in its current design since 1946, has a diameter of 17.91 mm (0.705 in) and an area of 251.9 sq. mm.
It's about twothirds as big as a Penny
In other words, 181 square millimeters is 0.6350 times the size of a Penny, and the size of a Penny is 1.570 times that amount.
(United States onecent coin) (a.k.a. Lincoln penny, a.k.a. Cent, a.k.a. One cent piece)The Lincoln penny, in its current design since 1909, has a diameter of 19.05 mm (0.75 in) and an area of 285.0 sq. mm.
It's about half as big as a Nickel
In other words, 181 square millimeters is 0.51230 times the size of a Nickel, and the size of a Nickel is 1.9520 times that amount.
(United States fivecent coin) (a.k.a. Jefferson nickel)The nickel, in its current design since 1938, has a diameter of 21.21 mm (0.835 in) and an area of 353.3 sq. mm.
It's about half as big as a Postage Stamp
In other words, the size of a Postage Stamp is 2 times 181 square millimeters.
(average; United States dimensions)A typical postage stamp measures an average of 400 sq. mm. One of the most prized stamps among collectors is the USissued "Inverted Jenny" stamp printed in 1918, which features an upsidedown image of Curtiss JN4 ("Jenny") airplane; a single stamp sold for $977,500 at a 2007 auction.
It's about twoandahalf times as big as a Nailhead
In other words, 181 square millimeters is 2.3280 times the size of a Nailhead, and the size of a Nailhead is 0.42960 times that amount.
(for 11gauge wire nai)An 11gauge nailhead measures 77.740 square millimeters. Nails have been used since ancient times; archaeologists have discovered Ancient Egyptian nails that are over 5,000 years old.
It's about twofifths as big as a Quarter
In other words, 181 square millimeters is 0.39160 times the size of a Quarter, and the size of a Quarter is 2.5540 times that amount.
(United States quarterdollar coin) (a.k.a. Quarter dollar, a.k.a. Washington quarter, a.k.a. two bits)The George Washington quarter, in circulation in various forms since 1932, has a diameter of 24.26 mm (0.955 in) and an area of 462.2 sq. mm.
It's about onefourth as big as a Secure Digital (SD) card
In other words, 181 square millimeters is 0.240 times the size of a Secure Digital (SD) card, and the size of a Secure Digital (SD) card is 4.20 times that amount.
A Secure Digital (SD) card measures 3.2 cm by 2.4 cm for a total area of 770 square millimeters. SDXC Cards, the latest standard for the technology, will allow the cards to hold up to 2 terabytes of data.

