How big is 306 square millimeters?
It's about one-and-one-tenth times as big as a US Penny
The size of a US Penny is about 285 square millimeters.
(United States one-cent coin) (a.k.a. Lincoln penny, a.k.a. Cent, a.k.a. One cent piece)
It's about nine-tenths as big as a US Nickel
The size of a US Nickel is about 353.30 square millimeters.
(United States five-cent coin) (a.k.a. Jefferson nickel)
It's about one-and-one-fifth times as big as a US Dime
The size of a US Dime is about 251.90 square millimeters.
(United States ten-cent coin) (a.k.a. Roosevelt dime)
It's about four-fifths as big as a Postage Stamp
The size of a Postage Stamp is about 400 square millimeters.
(average; United States dimensions)
It's about two-thirds as big as a US Quarter
The size of a US Quarter is about 462.20 square millimeters.
(United States quarter-dollar coin) (a.k.a. Quarter dollar, a.k.a. Washington quarter, a.k.a. two bits)
It's about two-fifths as big as a Secure Digital (SD) card
The size of a Secure Digital (SD) card is about 770 square millimeters.
It's about four times as big as a Nailhead
The size of a Nailhead is about 77.740 square millimeters.
(for 11-gauge wire nai)
It's about one-twentieth as big as a Post-it® Note (3M)
The size of a Post-it® Note (3M) is about 5,400 square millimeters.
(3M) (generically sticky notes, a.k.a. repositionable notes, a.k.a. repositional notes)
It's about one-twentieth as big as a Playing Card
The size of a Playing Card is about 5,600 square millimeters.
(ISO 216 B8 size)
It's about one-one-hundred-fiftieth as big as an Apple iPad
The size of an Apple iPad is about 40,020 square millimeters.
(for 9.7 inch, Apple iPad Air MD785LL/B)
It's about one-three-hundred-fiftieth as big as an Airplane Tray Table
The size of an Airplane Tray Table is about 101,000 square millimeters.
It's about 450 times as big as a Ballpoint Pen Tip
The size of a Ballpoint Pen Tip is about 0.70 square millimeters.
(a.k.a. Biro, a.k.a. ball pen, a.k.a. dot pen) (for medium tip)
It's about one-three-thousand-five-hundredth as big as a Bath Towel
The size of a Bath Towel is about 1,083,800 square millimeters.
(for Fieldcrest Luxury Solid Towels)
It's about one-fifteen-thousandth as big as a King Size Bed
The size of a King Size Bed is about 4,030,000 square millimeters.
(North American/Australian standard; length; mattress only)
It's about one-fifty-thousandth as big as a Parking Space
The size of a Parking Space is about 15,000,000 square millimeters.
(a.k.a Parking Stall) (average; surface lot; North America)