How big is a football next to an AA battery?
A football measures 22 cm (8.66 in) across, and an AA battery measures 5.05 cm (1.99 in) from the ground up. A football comes to 4.36 times the measured size of an AA battery, a difference of 16.9 cm (6.67 in). The two are not judged on the same axis: a football is quoted as a diameter and an AA battery as a height, so the honest statement is one figure against the other, 23% of it, and not one outline against another. A football is written in tens of centimetres and an AA battery in single centimetres, a whole band of scale apart.
| Object | Real size | Axis measured | What the figure covers |
|---|---|---|---|
| Football | 22 cm 8.66 in |
Diameter | FIFA Size 5 |
| AA Battery | 5.05 cm 1.99 in |
Height | IEC R6 |
Both figures, Football and AA Battery, come from the Size It Up measurement set, one real-world size and one measured axis per object, last checked in September 2026; outline provenance is listed on the sources page.
Why this one is hard to judge by eye
A football is drawn about 15.2 times as wide as an AA battery as well as 4.36 times its measured size, so the area it takes in the frame grows faster than the figure anyone quotes. Both shapes fit in a single glance here, which ought to make 4.36 to one obvious between a football and an AA battery, and it is not: at this size the eye compares whole outlines while the figures above compare one axis. On the drawing above a football is about 1.00 times as wide as it is tall and an AA battery about 3.48 times as tall as it is wide, so the two outlines fill the frame in ways that have nothing to do with the one axis being compared.
What each figure covers
Football. A size 5 ball has its circumference fixed by the laws, not its diameter. The height given here is the diameter that circumference implies.
AA Battery. The 50.5 mm covers the cell and its contacts. Battery compartments are built a millimetre or two longer, so a slightly loose fit is normal rather than a fault.
A football is quoted as a diameter and an AA battery as a height: two conventions, so the ratio compares the two numbers rather than the two objects.