Lateral 2πrh; total adds 2πr².
Right circular cylinder: lateral (side) area 2πr h and total surface area 2πr h + 2πr² (includes both circular ends). Inputs are radius and height as positive real numbers in the same length unit.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.