No, my 6.75yo switched to a 20" at 5

I would get the 16in. If you buy something like Woom or Guardian, they hold their value well so it would be the loss of about $50 in depreciation.

Unless your 6 year old is really small, get the 20”. Unless you live somewhere warmer they won’t be riding the bike frequently for the next 4 months. A lot of growing can happen then.

My vote is cheap 16.5 bike now. Better quality 20" later. I've had to swap the bikes out about every 2 years. I liked the idea that my kid could fully handle the bike by not getting them a big bike that was awkward.

As long as the kid's feet can touch the ground (or at least one foot) while seated and both feet while standing over the top tube; that should be a good idea of fit also.

No I bought my 6yo a 20 inch. The frame was kinda low though.

Or go for the 20 for longevity?