Gridlines and unit intervals

Use gridlines sparingly. There should usually be between four and eight gridlines per chart, depending on the size of the chart and the level of data. They should provide enough reference points to read the data values in the chart easily.

Don’t use too many gridlines.

Don’t use too few gridlines.

Do

Choose sensible gridline intervals.

Do

Don’t

Gridlines should always be grey: RGB value (190,190,190).

Don’t