Define linespacing using a Point-Value

i have to write a paper where the chair claims a font size of 12pt AND a line-spacing of 15pt (which seems 开发者_JS百科not to be \onehalfspacing).

Can anyone tell me how to define the spacing using the value 15pt?

Best regards and thanks! Philipp

You can set the line spacing exactly by altering the \baselineskip value.

\setlength{\baselineskip}{15pt}

Note that you have to use this command inside the document environment in order for it to have an effect.