
It's about as big as a Dime
(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 0.000000025190 hectares.
It's about ninetenths as big as a Penny
In other words, 0.000000025190 hectares is 0.8840 times the size of a Penny, and the size of a Penny is 1.130 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 0.00000002850 hectares.
It's about seventenths as big as a Nickel
In other words, 0.000000025190 hectares is 0.7130 times the size of a Nickel, and the size of a Nickel is 1.4030 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 0.000000035330 hectares.
It's about threefifths as big as a Postage Stamp
In other words, the size of a Postage Stamp is 2 times 0.000000025190 hectares.
(average; United States dimensions)A typical postage stamp measures an average of 0.0000000400 hectares. 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 half as big as a Quarter
In other words, 0.000000025190 hectares is 0.5450 times the size of a Quarter, and the size of a Quarter is 1.8350 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 0.000000046220 hectares.
It's about onethird as big as a Secure Digital (SD) card
In other words, the size of a Secure Digital (SD) card is 3 times 0.000000025190 hectares.
A Secure Digital (SD) card measures 3.2 cm by 2.4 cm for a total area of 0.0000000770 hectares. SDXC Cards, the latest standard for the technology, will allow the cards to hold up to 2 terabytes of data.
It's about three times as big as a Nailhead
In other words, 0.000000025190 hectares is 3.240 times the size of a Nailhead, and the size of a Nailhead is 0.30860 times that amount.
(for 11gauge wire nai)An 11gauge nailhead measures 0.0000000077740 hectares. Nails have been used since ancient times; archaeologists have discovered Ancient Egyptian nails that are over 5,000 years old. 
