how do I measure curtains?

[helsi]

I have some curtains to sell and want to advertise the size. When I take them down do i take all the gather out of the top first and then measure them across and down to the bottom?

sorry but I am no good with fabric or anything like this so I have no idea.

Measure from top to bottom along one edge so you know it's straight and then along the hemmed bottom to give you the width - the hem will be ungathered! I think the actual width of the curtain is usually roughly 2 x the width of window it is designed to fit but giving the measurement of the actual curtain should be fine..

thanks