Average Curtain Sizes
It is not enough to judge the quality of curtains by their 
design or color. One should also be able to properly estimate their measurements so as to not have them either falling too short or falling way down to floor.
In gauging the average size of a curtain, the terms of measurement used are width and drop. For instance, if one is buying a curtain measuring 45”x54”, the width would be 45” and 54” would be the drop. If one is buying drapes in pairs, the particular size will refer to each of the curtains, not both combined; so one would be getting two curtains with the same measurements.
To find drapes with just the right size, one should start by determining their track pole width. Ideally, the curtain’s pole position should be 15 cm (6”) over the window. The curtain must also extend by 16 cm (6”) on both of the window’s sides, but not including the finials.
In order to attain the complete look, the pole fit has to be up to 122 cm (48”). In this particular instance, the curtain’s measure should be 117 cm (46”). If the pole fit measures 48” to 66”, the measurement of the curtain should be 168 cm (66”). A pole fit from 168 to 228 cm (66” to 90”) should be equal to a curtain measuring 228 cm (90”).
When computing the average size of a pair of curtains, the width of the two pieces should be 1 ½ times the pole or track. Again, the finials are excluded. In considering the curtain’s length, one should make sure if the curtain will be able to fit the window sill. One should also think about whether the length will be just below the window sill or if it would reach the floor.
If the curtains will be the length of the window sill, the measurement above the sill should be 1.5 cm (1/2”). Drapes with a length just below the sill should reach below it by 15 cm (6”). As for curtains of floor length, they should be 1.5 cm (1/2”) above the surface of the floor.
In taking curtain measurements, it is useful to have a metal tape measure handy. When getting the width, one should be certain that there is a space of 3” (75 mm) on each of the sides. If one is measuring the track with the 3” tape heading, the measurement should start from the top of the track. If measuring a curtain pole, begin from the ring’s eye. If one is employing the eyelet heading, the measurement should begin from the top of the pole, which would be around 1.5” at the pole’s top.
Aside from the curtain’s size, one may also want to consider their weight. The fabric that the drapes are made from, as well as their texture, can be an important factor in determining their weight. Depending on the material, curtains can be heavier or lighter even if they basically have the same size.
