You can set the margin to decimal values to get the exact spacing you need. For example, 0. 5 will result in a margin of half an inch.

Click View in the top menu bar. Click Show ruler to make the ruler appear.

Place your cursor in a single line to change just the margins for that line. Highlight multiple lines to change their margins at the same time. Press Ctrl+A (Windows) or ⌘ Cmd+A (macOS) to select everything in the document.

You can also drag the blue rectangle to change the first line indentation of paragraphs. For more Google Docs tips, check out how to add borders and easily move images.