How to figure out finished measurements and estimate fit BEFORE sewing a stitch

Hey y’all, today we’re going to be talking about pattern ease, and finished measurements, both things that you need to understand in order to figure out how a pattern will fit you. Which, in my experience, is the biggest thing holding people back from sewing their own clothes – they don’t know what size to choose or how to estimate how a pattern will fit so they don’t want to cut out their fabric and try. There’s a fear of “messing up”.
I’ve said it before and I’ll say it again – the best way to learn in sewing is by DOING. So if you’re frozen and don’t want to cut out a garment because you’ll ruin your fabric, get yourself some cheap fabric for the express purpose of learning. If you’re frozen because you don’t want to waste time, reframe that as investing time in learning to fit your body so you won’t waste time in the future. Whatever the stumbling block, figure out a way around it because you will learn so much more about fitting your own body by actually doing it than by reading about it.
In the video below, I talk about pattern ease, finished measurements, and ways to estimate garment fit BEFORE you ever cut fabric or sew a stitch. You can also watch on YouTube here if you prefer.
What is pattern ease?
Pattern ease is the difference between the finished measurements of a garment and the measurements of your body. Ease is used to create style lines, for garment function, and to allow for movement of the body. Ease varies depending on the area of the body covered by the pattern. For example, ease at the waist in pants and skirts is usually minimal, just enough for you to breathe. You don’t want excess waist ease in pants or skirts because then the garment will fall off your body. On the other hand, more ease is generally needed in the hips so that you can walk and sit.

Patterns can have no ease, positive ease, or negative ease. No ease means that the finished garment measurements match the body measurements. Positive ease means that the finished measurements of the garment are bigger than the body. Negative ease means that the finished measurements of the garment are smaller than the body.
Patterns with no ease are usually drafted for knit fabrics, where the necessary ease for movement comes from the fabric’s ability to stretch. Patterns for wovens almost always have positive ease for movement, though the amount of ease might change through the garment as mentioned in the waist/hips example above. Formal wear might have no ease or even a small bit of negative ease in places to help sculpt the body, especially when combined with firm linings, boning, and other shaping techniques (think about wedding dresses, for example). Patterns with negative ease are generally drafted for knit fabrics and use the fabric’s stretch to allow or suppress movement. Think of things like swimsuits, compression leggings, etc.
Because beginning sewists don’t always have a firm grasp of pattern ease, I do not include most finished garment measurements in my patterns. I have found it can get very confusing for new sewists to try to decide what size to make when confronted with finished measurements that are different than the body measurements on the size chart. In general, if you go by your body measurements on the pattern size chart to choose your size, you’ll get a garment with the same amount of ease as pictured on the pattern model. Now this can get tricky when there are only illustrations of the finished garment and not photos, but choosing based on the size chart is a good rule of thumb.

How to calculate finished measurements
Of course, finished measurements can be handy when you understand their use. This is especially true if you find you tend to prefer your garment to be more fitted or looser than the pattern picture. Luckily figuring out finished measurements when they aren’t provided is easy.
- If your pattern includes seam allowances, mark off the seam allowances (blue lines above). Remember that if there is a fold, there is no seam allowance on that edge.
- Measure the area of the pattern for which you want a finished measurement. If this area is not marked on your pattern, you can hold the pattern up to your body and mark it. For example, if you wanted to mark a bust point, hold the pattern up to yourself and mark your own bust point.
- In the example above, to determine the finished bust, you’d mark the bust point, then measure from the side seam to the front fold at that level on both the front and back pattern pieces. Add those numbers together and you get one-half of the bust measurement. Multiply that number by 2 for the full finished bust circumference.
- If your pattern has multiple pieces that cover that area of the body (example: a princess seamed garment), make sure to measure each one.

Another tip to estimate how a pattern might fit you when sewn is to compare it to an item of clothing you have. Mark out your seam allowances and then compare the finished garment to the pattern. In the image above, you can see that the t-shirt from my closet is very similar in shape to the pattern I’m comparing it to. This is elaborated more in my video above.
I hope all of that helps you take some of the guesswork out of figuring out how a sewing pattern will fit you!
Barbara C
This is a great topic and I’m so glad you covered it. This is new to me, and I plan to use it on my next project! Thank you