Below you will find two short videos for no nonsense measuring!
I have seen so many intricate diagrams and long winded YouTube videos, drastically over complicating how to measure a window for curtains or blinds.
When measuring for curtains it is best to have a pole in place already but if you are yet to install one, measure from where the top of the pole would go, as this will allow enough fabric. Then once the pole is in place you can take final measurements.
Comment below if you have any further questions.
Measuring guide for roman blinds
Measuring guide for curtains