Here is a simple chart.
Curtain rod length calculator.
Source the most common mistake that people make when measuring for off the shelf drapery is the rod itself.
For a more advanced calculator try this one.
To make your windows appear wider and higher as you should add a few inches to your measurements.
You calculate curtain length with double curtain rods the same way you calculate the length for single curtain rods measuring from where you ll install the rods to where you want the curtains to.
I see this so often i decided to write a post so that at least all my readers will be in the know.
This would result in all 48 inches of window glass showing when curtains are fully opened.
To accomplish that you would need to make sure the curtain rod is at least 20 inches larger than the original window size of 48 inches or 68 inches.
This will give you the length of your curtain rod.
Using a steel measuring tape measure the width of your windows inside your frame.
Determine rod length before you measure your window for width it s best to choose the length of your curtain rod.
Input all info please.
Measure from the inner edge of one side of your frame to the other.
However because rods can be installed either inside below or above trim mount determining where you install your rod affects the length.
Wallace racing back to calculators this calculator will figure the rod length using your inputs.
In the photo.
This look offers a few advantages.
How to measure for the correct curtain length grab your trusty measuring tape and take your measurements from the floor to where the rod will be placed.
Stack back is the amount of space the curtains occupy when in the fully open position.
Source interior design by steven gambrel your drapery rod should generally be 10 15 inches longer on each side of the window to allow for the fabric to hang on each side.
In traditional style the curtain rod is about 6 inches above the top of the window and it extends beyond the window 3 inches on each side.
Please note that the calculation of the stack back width is only an estimate stack back can fluctuate depends on factors such as puddling fabrics lining options curtain rods brackets and rings.
The curtain will hang 3 inches below the bottom of the window sill.
We typically add 5 inches to each side of the frame for windows up to 50 inches wide then add another 2 inches for each additional 10 inches of window frame width.