1.45669 inches OD small to be precise. Teleflora wheels are nicely detailed!
Just a bit larger (1.55 inches OD) are the American Girl kettle wheels.
Reason for the post is that I just bought a refurbished (well, new actually) Canon G15 and the macro on it is much better than my G11 that is having issues. I know we have a few camera buffs here in the club - I'm just a hack. I do really like the G-series format; small, tough, and does 95% of the stuff I normally shoot. The G15 has a much better lens than before. Until mirrorless comes down in price I'll stick to this series. I paid $249 direct from Canon and it has the full one-year warranty. Should last many years. Not trying to sell cameras here, just thought some of you might be interested.