It is always best to measure up for curtains with your pole or track already in place otherwise there will be too many unknowns to get accurate results.
Use a metal tape! They are more rigid and will give a more accurate measurement. For the best performance, your curtain track or pole should be positioned approximately 15cm (6”) higher than the window, and be wider than your window by at least 15-20cm (6-8”) either side.
If you’re using a curtain track, measure its full length. For curtain poles measure the length of the pole only, do not include the finials (decorative pieces on the end).
Decide where your curtains will end. Sill length curtains should finish either 1.5cm (1/2”) above the windowsill or 15cm (6”) below the sill to exclude lights and draughts effectively. To prevent wear on the hems, floor length curtains should ideally finish 1.5cm (1/2”) above the floor.
Windowsills and floors are not always level, so measure at 2 or 3 points to ensure the best fit. Measuring at either end and in the middle should provide accurate results.
To measure the ‘drop’ of your curtains for pencil pleat, measure from the point where the curtain hook will sit to your chosen end point (e.g. windowsill or floor). For curtain poles, measure from the bottom of the pole rings to where you want the curtain to finish.
Ensure there are no obstructions that would get in the way of the blind such as tiles or phone sockets. Take the measurement from the very top of the window recess down to the top of sill and across the full width of the window recess, taking three measurements in each case and use the smallest measurement.
For blinds fitted across the opening, again take your measurement from the top of your window recess down to the bottom of your sill and across the full width of the window recess. Then allow 5cm overlap all the way around to ensure full coverage and between 15 and 25cm at the top, depending on whether you would like the blind to sit above the recess when fully drawn or overhanging it slightly. I will then calculate how much fabric you need (including allowances for hems and pockets etc). If you want a wider blind than your window + 10cm, or a longer drop just let me know.