Whether you’re a beginner or experienced sewer, you’re never safe from falling in love with a fabric and absolutely wanting to buy it for a project... and then the question quickly arises... "yes, but how much...?" And the risk when making your project is having too much or too little. 

I suggest we go through my tips together to calculate (when you have planned ahead) or estimate your fabric needs (when you have a crush on a fabric) so you won’t be caught off guard.

First scenario: You have planned your sewing project and want to buy the fabric accordingly.

This is the ideal situation because you will be able to buy exactly the amount of fabric needed for your project, without waste.
If you plan to make a commercial pattern, you can refer to the designer’s advice who will have listed the required yardage by size. It should be noted that the fabric requirement often increases significantly from size 44 onwards. This is because it is often no longer possible to place two pieces within the fabric width. 

Next, I invite you to check the cutting layout if it is provided with your pattern. Often, it’s possible to optimize this layout to use less fabric than what is indicated in the model. For example, you can place pieces head to tail. This is only possible under three conditions:

• respect the grainline direction when placing the pieces
• respect the direction of the pattern 
• allow for extra fabric for possible matching.

Imagine an animal print fabric where the animals are sometimes right side up and sometimes upside down depending on the pieces, or a plaid fabric with no matching at all. On the other hand, there’s no problem with solid fabrics, dots, and some floral or small repetitive patterned fabrics. 

To be as accurate as possible, I use a really effective method starting by tracing my pattern (including seam allowances) and then placing the pieces on another fabric of the same width as the fabric I want to buy for my project. Then, I test my "puzzle" to try to arrange the pattern pieces as efficiently as possible. It has also become a little challenge with myself. 

Just be careful about how many times you need to cut the piece and add a little extra for the normal shrinkage of the fabric when washed. Feel free to check out my article on fabric washing for more on this.  For my part, I always add at least 10cm.  

 Once this test is done, all that’s left is to order and have fun!

Second scenario: You have a crush on a fabric.

First question to ask yourself: "What is the width of the fabric that I love?"

Indeed, fabrics produced in Asia, Africa (notably wax prints), and the United States very often have a width around 110cm, while fabrics produced in Europe very often have a width around 140cm. This will clearly impact the fabric requirements for your project. 

Second question to ask yourself: "For what type of garment am I reserving this fabric?" 

You probably guessed right away, the yardage needs will vary greatly if I decide to sew a sleeveless summer top or a long-sleeved dress. So it’s better to decide on the type of garment you want to sew: dress, pants, blouse (with or without sleeves). 

Third question: "For whom and in what size will I sew this garment?"

Obviously, the yardage requirements will vary greatly if you decide to sew a dress for a 4-year-old girl, a teenager in size 34, or a plus-size woman.

For reference, here is what I use to calculate fabric needs for my sewing projects.
This chart is valid up to size 44 and remains an approximation. 

Third scenario: you fall in love with a fabric and have no idea what you will make with it...

Let's be honest, this is the worst-case scenario but it can happen... so to avoid this fabric ending up unused in your stash due to lack of a project... In these cases, make sure you know if it is indeed a fabric suitable for making clothing or accessories (depending on what you like to sew) and take note of the fabric type so you can later choose a pattern adapted to its type (woven vs jersey; natural fibers vs synthetic...).

The ideal in these cases is to buy 3m because with 3m, whether the width is 110cm or 140cm, you will always be guaranteed to be able to make one or two pieces of clothing from your coupon. 

I hope you enjoyed this article and that it will be useful for your shopping.