¿How much fabric do I need?

How much fabric do i need to buy? ... is the question we often do when we prepare to make a garment. And most of the times we get fabric only guessing the approximate quantity we will use, which not always works since we end up by buying too many fabric or not enough.

To calculate the exact amount of fabric that you need, there are certain formulas and previous knowledge you need to know. Keep reading and i will explain you the proper way to calculate how much fabric you need and how to cut it to make the most of it :)

Previous Knowledge

There are some things you need to know about your fabric that will help you to plan everything as well as use the less amount of fabric as possible in order to get  the perfect garment.

Parts of the fabric:

Fabric grain refers to the way threads are arranged in the fabric, and depending on their direction or size we give them different names and use it as we need to get different effects on the final garment.

Lengthwise grain - fig. 1: we give this name to the side way of the fabric with longer threads (called also warp threads -  fig. 2 ), these are going continuously along the length of the piece as it comes from the bolt.

When you go to the fabric store and ask for 1 mt of fabric, they will measure it by this side.

Crosswise grain - fig. 1: side of the fabric piece which is perpendicular to the lenghtwise, is made up of shorter threads (called weft threads - fig. 2), and its length is considered the fabric width.

When you go to the fabric store and ask for some fabric, they open the bolt, measure the mts you want and cut along the crosswise grain to get your piece of fabric.

Selvages: are the limit edges of the fabric going along the lengthwise grain extreme. You can recognize it because these extremes of the fabric are very tight for a half-inch or so keeping the edges stable while fabric is on the bolt. fig. 1

Bias: direction of the fabric which is going at 45 degrees angle from the straight grains and it helps to get stretch cuts of fabric.

 

Fig. 1 ☝

Fig. 2 ☝ 

Green lines represent warp threads

Brown lines represent weft threads

 Fabric Width

Depending on the country where are made or the kind of material, and other factors, the fabrics come in diferent width, and you must ask in your fabric store how wide is the fabric you want before to buy it or calculate how much you need.

As we said, the width of the fabric is given by the lenght of the crosswise grain and we can find most frecuently are the following sizes:

• 90 cm
• 1.10 mts
• 1. 20 mts
• 1. 50 mts
• 1. 80 mts
• Doubble width ( more than 1.80 mts)

 But... why do you need to know all this?

Because doesn't matters how wide your fabric is, you must follow the lengthwise grain when cutting the pieces of your garment, otherwise the fabric will not fall properly once you wear it, and it will look twisted. Fig 3 .  

Only for specific purposes you can follow the bias or the crosswise grain. 

Follow the bias when you want to get stretch in your garment.

For some special effects with printed fabrics you can alternate the pieces cutting them in crosswise or lengthwise grain alternatively.

 

Fig. 3 ☝ 

  

Now you know all the basics, i will explain you how to calculate the ammount of fabric you need to get...

You will need to know 2 things: 

• how wide you need the fabric to be
• how much meters of fabric you need to get 

Knowing that you must follow the lengthwise grain while cutting, let´s take the following example. Pay atention to the measurements you need to know:

Once you know and make note of all information about your garment ( you must consider every piece such as body, sleeves, etc), use this formula to know how wide must be the fabric you get:

Fabric width you need= (widest part of your garment x 2) + 10 cm

For this example it would be: 

70 x 2 = 140

   140 + 10 = 150 

so i need my fabric to be at least 1.50 mts width.

Now lets see how much fabric you will need:

CASE 1

* If you find the fabric with the width you need (or is 1.50 mts or more width), then use this formula:

(Length of garment + sleeve length) + 20 cm

and place your patterns as shown below:

For our example:

85 + 50 = 135

   135 + 20 = 155

So i will need 1.55 mts of fabric

CASE 2

*When your fabric is  1.10 or 1.20 use this formula

 (length of garment x 2) + 20 cm

and place your patterns as shown below:

In this case our fabric is not enough to cut front and back body sides together as in the last example, but if we add the widest part of our garment and the total widht of the sleeve it will be enough to cut the sleeves and the body parts sides together as in the illustration.

So we have:

85 x 2= 170

  170 + 20 = 190

So i will need 1.90 mts of fabric

CASE 3

*When the fabric is 90 cm

 (length of garment x 2) + (sleeve length) + 30 cm 

For our example:

85 x 2 = 170

   170 + 50 = 220

   220 + 30 = 250

So i will need at least 2.50 mts of fabric

and place your patterns as shown below:

And that is all, now you know how to calculate the amount of fabric you need to get for your next sewing project, i recomend to round off the numbers, for example for the case 2 i would get 2 mts of fabric, for the case 3 i would get 2.50 mts.

If you have any doubt leave a comment or contact me on my fb page 

happy stitches for everyone <3

Sandi