How to Make Curtains | Home Makeover Tutorial

Lesson 8 – How to Measure for Curtains

How to Calculate Curtain Yardage | Curtain Yardage Calculator

Bear with us for this lesson folks, measuring out your curtain fabric is a bit more complicated than it looks. The reason being because you are working with 4 variables: the curtain height, the curtain width, the desired amount of gathering, and the fixed fabric width – the bolt size (which also varies). So there's really no one correct way to measure for curtains. However, Lisa has carefully prepared a very convenient formula for you to use! Yes, a math equation that will help you accurately measure out enough fabric to make curtain panels to cover a customized window size.

BUT FIRST, a Quick Result – Curtain Yardage Calculator:

Just plug in your width and height into this spreadsheet and find your needed yardage! Click the image, or view it here.

The calculator we created does the math for you. Plug in your measurements to calculate your yardage. Your end result is the amount of total yards to order of the desired curtain fabric.

Still curious for the who-what-and why? Allow us to nerd out for a moment…

As told by Lisa, our sewing instructor. Fabric comes in set bolt sizes. That basically means, the set width of the fabric. Most bolts come in a set width of 45 or 60 inches. You get to choose whatever length (warp, vertical) you want, but the width (weft, horizontal) is constant. With that in mind, what happens when your window is 80 inches wide? What happens when it falls between a set width? The idea is you have to round up, and either cut off the extra fabric on each side, or use it to your favor. So that's what I have done with this equation. Showing here:

Now that's so bad, right? Ok maybe math isn't your forte. Go back and plug in your measurements into the spreadsheet above! Still want to know how we got to that answer? Keep reading…

We take the Width of the window (W) and times it by the desired increase in curtain width to allow for a nice gathered look when curtains are drawn shut. This increase is commonly seen as 1.5 times the actual width. If you want to double your curtains in size for even more gathering, change this number to 2, want to go even higher? Use 2.5. Increase fabric width accordingly.

( W • 1.5 )

Then we divide that number by the width of our bolt of fabric. Which is typically 45 or 60. You'll know once you've chosen your fabric. Bolt size will be marked on the label at the base of your bolt in the fabric store. Do the calculation, then take your result and ROUND UP to the nearest whole number. If this number is odd, you'll have to cut one of your panels in half, if the number is even, you're in luck.

( W • 1.5 ) / 45 = X (ROUND UP TO NEAREST WHOLE NUMBER)

This number (X) indicates how many curtain panels you will need. For small windows, the answer will most likely be 2.  For anything larger, like a patio door, the answer will be 4 or more. If your number is odd, then you will need to cut one of your curtain panels in half add one of each halves to 2 of your other curtain panel. This keeps the curtains balanced on both sides of the window.

Now you need your length. Take the height of the window (H), and add 12″. This accounts for the curtain heading, the hem, and the break. This number can be adjusted if you so choose. I recommend going longer than shorter, since it is much easier to hem a curtain than let it out, or worse, have it be too short. Once you have your height, divide it by 36, to know how many yards your height in inches equals. (There are 36 inches in 1 yard). Yards are the measurement most commonly used when you cut your fabric.

(H + 12 ) / 36 = Y

Y is the length each panel of curtain will be. Now all we need to do is multiply the height times the number of panels. X times Y. This gives us a solid number of yards we need of curtain to get. From there you get to go home and cut up each of your individual panels, and hem all the edges!

X • Y = Yardage

Really though, just input your numbers into the equation… or the calculator! It's so simple that way!

There are more great tutorials (and less complicated tutorials) in our How to Make Curtains Series coming your way, just hit next or go back to the Table of Contents by clicking the links below!

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This is Lesson 8 of our How to Make Curtains Online Course: How to Measure for Curtains with a Curtain Yardage Calculator. It's part of our free Home Makeover Tutorials package! We want you to be able to fill your homes with amazing handmade diy crafts that you know how to sew yourselves! Our hope is that these sewing patterns and ideas inspire you to redecorate your living space and ultimately create your dream home! Imagine a personalized stylish home decorated exactly to your liking. Come home happy and enjoy the accomplished feeling of “I made this.” Here at DIY Projects we love inspiring dreams, and encouraging craftiness in all aspects of life. Be sure to subscribe to our social medias to stay connected on all things made by hand! Join us on Facebook, Pinterest, Instagram, and Twitter.