line-height attribute

Type:length, percentage (calculated with respect to the current height of the font), "normal"
Used By:All block elements

The line-height attribute controls the space between lines in a paragraph. The default value, "normal", sets the height to whatever value is recommended by the font-author - usually between 100% and 130% of the font-size. Alternatively you can specify an absolute value, eg. "14pt", or a relative size, eg "120%".

This sets the line height to 15pt

P { font-size:10pt; line-height:150%; }