The recommended wheel and tyre sizes should be.
Road bike tube sizes.
Mountain bike tyre sizes are usually stated in inches.
Bike inner tube size chart and my recommendations.
Kids bikes will have smaller wheels usually 16in 20in or 24in and need smaller diameter inner tubes and tyres as will most folding bikes.
Below is the list of my recommended inner tubes.
While you can find a variety of bikes with wheel sizes ranging from 16 to 27 5 inches the most common sizes include 26 inches 27 5 inches 29 inches and 700c.