Please follow the steps below to add the Gridlines to a Chart:
Step 1: Click anywhere on the chart and the "Design" Tab will appear in the Ribbon ("Chart Design" tab in Excel 2019);
Step 2: In the "Design" tab, click "Add Chart Element";
Step 3: Click "Gridlines" from the drop-down list, then select the following Gridline types "Primary Major Horizontal", "Primary Major Vertical", "Primary Minor Horizontal" or "Primary Minor Vertical";
Step 4: Here is the result of "Primary Minor Vertical" option:
Step 5: To change the number of "Gridlines", right click the Axis (e.g., Y Axis), then click "Format Axis" in the dialog box, and change the major units (e.g., 4);
Step 6: To format major Gridlines: double click on the Gridlines, in the "Format Major Gridlines" window:
– Click "Solid line";
– Change color "Gray";
– Change "Width" and other characters;
Step 7: Close the "Format Major Gridlines" window, the result of the chart with Gridlines.
To delete "Gridlines", click on one of the Gridlines, and press "Delete" key in the keyboard.
