Work out histogram class width instantly with clear inputs, formula shown and shareable results.
Sturges' rule suggests 1 + log₂n classes and the Rice rule 2∛n. Dividing the range by the class count gives the width, which is usually then rounded up to a convenient value.
Sturges' rule
classes = ⌈1 + log₂n⌉, width = range / classes
Rice rule
classes = ⌈2·∛n⌉
Sturges gives 7 classes of width about 10.71, so 11 or even 15 would be tidy choices.
Very much. Too few hides structure and too many produces a spiky, noisy histogram.