
It's about ninetenths as big as an Airplane Tray Table.
In other words, 138.19 square inches is 0.883 times the size of an Airplane Tray Table, and the size of an Airplane Tray Table is 1.13 times that amount.
(average)With wide variation among different models of airplanes, inflight tray tables measure around 41.2 cm (16.5 in) x 24.1 cm (9.5 in) for a total area of 157 square inches. Flight safety rules require that the tray tables be upright and locked during takeoff and landing so as to reduce the risk of passenger abdominal injury.
It's about two times as big as an Apple iPad.
In other words, 138.19 square inches is 2.228 times the size of an Apple iPad, and the size of an Apple iPad is 0.4488 times that amount.
(for 9.7 inch, Apple iPad Air MD785LL/B)An Apple iPad measures 23 cm (9.4 in) x 17 cm (6.6 in) for a total device area of 62.03 square inches. The base model iPad Air features 16 GB of storage capacity.
It's about onetenth as big as a Bath Towel.
In other words, 138.19 square inches is 0.082261 times the size of a Bath Towel, and the size of a Bath Towel is 12.156 times that amount.
(for Fieldcrest Luxury Solid Towels)Bath towels typically measure 142.24 cm (56 in) by 76.2 cm (30 in), for a total area of about 1,679.9 square inches. The city of Bursa, Turkey is known as the birthplace of the modern towel.
It's about sixteen times as big as a Playing Card.
In other words, the size of a Playing Card is 0.063 times 138.19 square inches.
(ISO 216 B8 size)A single ISO 216 B8size playing card measures 8.7 square inches. Although this size is the most common playing card, many casinos use the smaller "bridge size" card — 4.1 square inches smaller.
It's about seventeen times as big as a Postit® Note (3M).
In other words, the size of a Postit® Note (3M) is 0.059 times 138.19 square inches.
(3M) (generically sticky notes, a.k.a. repositionable notes, a.k.a. repositional notes)A Postit® Note measures 8.4 square inches in total area. In September, 1989, Hurricane Hugo swept through Charleston, South Carolina with winds up to 230 kph (140 mph), uprooting eight oak trees in Mr. Bruce Brakefield's yard, but leaving in place a Postit® note attached to his front door.
It's about onefortyfifth as big as a King Size Bed.
In other words, the size of a King Size Bed is 45.2 times 138.19 square inches.
(North American/Australian standard; length; mattress only)A KingSize mattress measures 6,250 square inches in total area. Although most antique beds were smaller than modern beds, it was not uncommon for beds in the medieval Europe to reach 7,750 square inches for those in positions of wealth or power.
It's about 100 times as big as a Secure Digital (SD) card.
In other words, 138.19 square inches is 120 times the size of a Secure Digital (SD) card, and the size of a Secure Digital (SD) card is 0.0083 times that amount.
A Secure Digital (SD) card measures 3.2 cm by 2.4 cm for a total area of 1.2 square inches. SDXC Cards, the latest standard for the technology, will allow the cards to hold up to 2 terabytes of data.

