Add up the width of every wall you're covering, measured at its widest point.
Example: 380 + 450 + 380 + 460 = 1670cm
Measure from the top of your skirting board (if you have one) up to the ceiling or coving.
You'll find this on the product page for your chosen design.
A handy guide, but handle your tape measure with care and always check with a professional before ordering.
