Answers for "material ui theme.spacing"

spacing material ui makestyles

const theme = createMuiTheme({
  spacing: [0, 4, 8, 16, 32, 64],
});

theme.spacing(2); // = 8

spacing material ui

const theme = {
  spacing: [0, 2, 3, 5, 8],
}

<Box m={-2} /> // margin: -3px;
<Box m={0} /> // margin: 0px;
<Box m={2} /> // margin: 3px;