Table tennis ball
40 mm (1.575 in)
Diameter
A regulation ping-pong ball. Diameter: 40 mm.
Published
How big is that?
40 mm is 47% of a credit card.
Table tennis ball is the 6th smallest of the 39 Classic objects, and the 6th smallest of the 109 objects across all three SizeItUp games.
Size comparison
To scale, smallest to largest: Table tennis ball in orange beside the Classic objects nearest in size, in teal.
| Object | Size | vs Table tennis ball |
|---|---|---|
| US quarterThe 25-cent coin of the United States. | 24.26 mm across | 61% of the size |
| LEGO brick (2 x 4)The classic eight-stud building brick. | 31.8 mm long | 80% of the size |
| Table tennis ball | 40 mm across | – |
| Golf ballA regulation ball for the game of golf. | 42.67 mm across | 1.1× bigger |
| AA batteryThe common cylindrical battery in remotes and toys. | 50.5 mm long | 1.3× bigger |
In other units
| Millimetres | 40 |
|---|---|
| Centimetres | 4 |
| Metres | 0.04 |
| Inches | 1.575 |
| Feet | 0.1312 |
How it's measured
Diameter. ITTF Laws of Table Tennis 2.3.1.
Sources
- documents.ittf.sport: ITTF Statutes 2026, Law 2.3.1: the ball shall be spherical, with a diameter of 40mm.
Checked against the source on .
Could you have guessed it by eye?
Table tennis ball is one of the objects in Classic, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.