How to Change Margins in Google Docs
Set custom top, bottom, left, and right margins in Google Docs from File, Page setup or by dragging the ruler, and save them as the default for new documents.
Every new Google Doc uses 1 inch margins on all four sides. You can type exact values in the Page setup dialog or drag the margins on the ruler, and either way the change applies to the whole document unless you limit it to a section or selection.
Open Page setup
Click File, then Page setup. Make sure the Pages tab is selected at the top of the dialog. The Pageless tab has no margin fields because a pageless document has no page edges.
Enter the margin sizes
Under Margins, type values in inches into the Top, Bottom, Left, and Right boxes. Decimals work, so 0.75 gives a three-quarter inch margin. Zero is accepted, but most printers cannot print to the edge of the paper.
Choose what the margins apply to
If the document has section breaks, or you selected text before opening the dialog, an Apply to dropdown appears. Pick Whole document to change every page, or the section or selection option to limit the change. Applying to a selection places section breaks around it so the rest of the document keeps its original margins.
Click OK or Set as default
Click OK to apply the margins to this document. To make them the standard for every new document you create, click Set as default first, then OK. Existing documents are not affected.
Or drag the margins on the ruler
If the ruler is hidden, click View, Show ruler. The gray areas at each end of the horizontal ruler are the left and right margins. Hover over the edge where gray meets white until the cursor becomes a double arrow, then drag. The vertical ruler along the left edge works the same way for the top and bottom margins. Take care to grab the margin edge and not the blue indent markers that sit on top of it, which move only the paragraph indent.
Paper size and orientation. The same Page setup dialog holds Orientation (portrait or landscape) and Paper size, so you can change all three at once. Letter size with 1 inch margins is the default.
In the mobile app. Tap the three-dot menu, then Page setup, then Margins to pick from the preset widths.