Sewing and Fitting the Perfect Plus-Size Jumpsuit
In this post I would like to share some great tips for fitting your first plus-size jumpsuit.
A jumpsuit is a perennial fashion favourite and is the perfect thing to wear whether you’re fixing your car or walking down the aisle. Fabric choice, accessories and a perfect fit all work together to make a jumpsuit an outfit that looks effortless whatever the occasion.
The perfect plus-size jumpsuit might feel like a unicorn. Ready-to-wear jumpsuits are rarely the right length in the torso and they either give you a wedgie or the crotch hangs so low that your thighs chafe. It might fit while standing, but sitting down is another matter!
Fitting a jumpsuit can be tricky because it means working with the whole body, which means fitting your top and your bottom, combining bodice fitting with pants fitting. It’s a fantastic opportunity to learn the fitting adjustments you need for your unique body.
Start with the right base size
Your fitting journey will go much more smoothly if you start with the right base size. Use the hip sizes in the size chart to determine which size to make. You want to make sure that the pattern has enough room for your fullest part, which is usually but not always your hips.
The Love Notions Sunday Romper and my hacked Chorus Romper both have a “stuff the human through the neck hole” method of entry, so it’s important that your hips and shoulders will fit through the neck opening. Knit jumpsuits and woven jumpsuits without closures are usually drafted to take this into consideration and will have a wide neck or elasticated neck to allow you to stretch it out and step into it and pull it up your body. (A woven pattern with this method of entry is the Avenir Jumpsuit from the Friday Pattern Company.)
TIP: If you have very narrow shoulders compared to your hips and you will have to grade out for your hips by more than a size or two, consider adding a button placket, keyhole or other closure to the neck or on one of the shoulders, to allow the smaller top to still fit over your widest point without falling off your shoulders when you wear it.
Sewing cup size
Choosing the right cup size is more important for a women’s jumpsuit than any other garment, because you need enough room for your bust without it stealing fabric from the torso length (that’s how wedgies happen!).
Love Notions patterns like the Sunday Romper have the full bust adjustment done for you, so if you have a difference of 4” between your high bust and your full bust, you can use the full bust pattern piece without having to do an FBA (Full Bust Adjustment). If you have a bigger difference than this and you’re working with a knit fabric, you can add more room by doing a ‘pivot and slide’ full bust adjustment which adds room without adding a dart. If your difference is 4”-5”, you can ‘cheat’ and use the full bust bodice and add a little extra to the bodice hem at the centre front, which is what I do.
Make your cut 1” from the bottom of the pattern piece to preserve any subtle shaping in the hem. True the edges after adjusting.
Increasingly, indie pattern companies are recognising that not all plus-size bodies have a D cup (a 4” difference), and some designers will draft their patterns for multiple cup sizes. Very handy if you’re a B cup bust with a 55”+ hip, or a C cup and stuck in that middle ground where you have to know how to do both a small bust adjustment and a full bust adjustment depending on which block the designer has used.
Torso length
If the pattern you choose lists the torso length (sometimes called girth) in the size chart, make a note of it. Torso length is the single most important measurement you will need for getting a good fit in the body of the jumpsuit. Your girth is measured from one shoulder, down the front and through your legs, up your back to the same shoulder.
How to measure your torso length (aka girth).
Girth takes into account your height and also your tummy and bum (but not your bust since the tape measure goes between the breasts, which is why we discussed cup size first).
If you have a prominent belly and/or bum you will need more length in the crotch and this will affect the girth measurement. We will deal with full tummy adjustments and adjusting the seat later in this post.
Putting it all together
It’s unlikely that the pattern you choose will be the perfect girth, cup size and hip size all in one pattern size, so you will have to do some fitting adjustments. If you are between hip sizes and the girth is listed in the size chart, go for the hip size with the girth closest to yours. It is easier to adjust the side seams than to add or remove girth.
If you would rather go by your hip size and adjust the pattern for your girth, it’s a bit more involved, but it is possible. You will need to add length in several places: shoulder to bust, bust to waist (sometimes called your ‘side waist’), and waist to crotch. How much you would add in each of these places will be determined by your body measurements. Try measuring your body and comparing it to these three sections of the pattern. Remember to add to both the front and back pattern pieces of the jumpsuit, and if the pattern has separate bodice and pants pieces, make sure you add to both of these too.
These three measurements will be unique to you and when you add or remove torso length, make sure to add or remove the correct amounts in each place.
Make your usual fitting adjustments first
This step is a time saver and can reduce the number of adjustments you need to make to your toile (muslin). It will be most successful if you have worked in a similar fabric before and know the adjustments that you usually need to make. These include but are not limited to:
Height (not to be confused with torso length, but they are related)
Bust (volume and apex height)
Shoulder width
Shoulder slope
Rounded back (if the pattern has a high back neck, do this now)
Back length (if you know you usually need a large swayback adjustment, taking out a little wedge at the back waist now can reduce how much you need to adjust your muslin by later)
Leg length (some fitting adjustments that alter leg angle should be done to the whole leg piece)
Crotch rise (but only if you routinely adjust the rise in patterns by the designer you are using)
Make a muslin
You will want to get a good fit with your muslin before using your fashion fabric, so you may need to make more than one muslin. When fitting the Chorus Romper I made two muslins, one using my correct base size with no adjustments, and the second one to check that the adjustments I had made had improved the fit and didn’t need further tweaking.
To save fabric and time, make your muslin in shorts length, leave out any pockets (we’ll add them back in, don’t panic), and make the sleeveless option or leave off the sleeves for now. Do staystitch the armscye, as trying on the jumpsuit will stretch this area by a surprising amount. If you anticipate having to wriggle to get into your muslin, consider adding a bias facing (for wovens) or bands (for knits) to the armholes for extra security.
I left the armscye raw on my first muslin and it stretched by several inches, distorting the armhole to lend fabric to the front bodice (which really needed length added).
It’s very unlikely that your first attempt will result in a wearable toile, even if you do all of your usual fitting adjustments on the pattern before making it up. So use your cheapest fabric first and save your better fabric for next time.
Assess the fit
Hopefully you can get into your first muslin. Don’t worry at this stage if it gives you an atomic wedgie or if the crotch is at your knees. We will deal with these things now.
Atomic wedgie (too tight in the crotch)
If your muslin is trying to cut you in two, it’s very likely that you need more length in the torso (girth). Assess the front and back of your muslin and try sitting down to see where it’s tight. Try to determine whether it needs length all around the middle (even wedgie front and back), or if it’s actually a crotch length issue (you have either a hungry bum or camel toe but not both).
If it needs length all around the middle, you can determine how much by slipping the jumpsuit off your shoulders and lowering it until the wedgie disappears. Make a note of roughly how much this is. You can estimate by placing a clip or safety pin at your belly button and noting how much it moves down as you lower the jumpsuit. You will then adjust your pattern pieces by the same amount. You will adjust the front pieces and the back pieces by slashing horizontally and adding extra paper.
If it’s a crotch length issue, take the muslin off and turn it inside out. Try scooping the crotch 1/8”-1/4” where the wedgie is. Put the muslin back on and see if that has improved the fit. If that doesn’t help, or if you scoop ¼” and it’s not enough, go back to the mirror and reassess. Is your muslin pulling down at the front waist? If it is, try a full tummy adjustment. If it’s pulling at the bum and you have diagonal lines going from the hips into the bum, try a full seat adjustment.
When the waistband is pulled up so it is almost level on the waist the tummy area becomes tight to the body. Slashing and pivoting the pants front pattern piece to add a small wedge at the centre front at belly button level and tapering to nothing at the side seams lengthens the front crotch rise and adds space for my prominent tummy.
Baggy Crotch
If your muslin is hanging low at the crotch it’s likely that the torso length is too long for you and you need to remove length in the body. You’ll need to determine whether the extra length needs to be removed from the bodice, or from below the waist. Pull the waistband up so that it sits at the natural waist. Does that resolve the low crotch? If so, look at the bodice and how it blouses out. Assess how much fabric is blousing out. Is it too much? Or just right?
If the bodice is blousing out just right and the crotch fits when the waistband is sitting on the natural waist, then the issue is very likely to be that you need a shorter piece of elastic in the waistband, or stronger elastic so that the waistband sits at the waist and stays there. You may need to try ‘heavy stretch’ elastic that’s strong enough to hold the weight of the fabric. Or you could try widening the waistband casing and using a wider piece of elastic as sometimes wider waistbands can be tighter than narrow waistbands without cutting in.
If the bodice is blousing out too much and there’s excess fabric above the waistband when the waistband is in the right place, then you need to remove length in the bodice. In a woven jumpsuit with a bust dart you will need to check that the bust fits well before deciding where to remove length. Check that the dart points to your apex, and that the fabric on your upper chest is sitting flush against your body. If you have puffiness above your bust, pinch out a wedge across your chest and clip it, and check if that improves the fit.
If your bust fits well, or you’re using a knit, you will remove length from the bodice instead. Determine how much to remove by pinching the excess fabric close to the waistband and clipping it. Check the back to assess whether you need to remove the same at the back as at the front. Transfer these adjustments to your pattern pieces by measuring how much fabric you clipped and removing that amount from the bodice bottom. If the bodice has a curved bottom, make your adjustment an inch higher by slashing and overlapping the pattern piece.
Baggy seat (but the tummy fits well)
If your muslin fits well at the front crotch but feels baggy in the seat, you may need to make a seat adjustment. The Sunday Romper in particular assumes a rounded bottom with lots of volume. I have a swayback and a low seat, so this shape needed changing for me to get a good fit. I pinched out length in the back crotch about 3” down from the waistband to make a flat seat adjustment. It’s important to note that any adjustment is relative to the pattern, so I may not have a flat seat per se, I have a seat that is flatter than the pattern is drafted for.
Before (left) shows a baggy seat with too much length in the crotch. After clipping out a wedge of fabric at the top of the bum the fit is greatly improved (right).
Baggy tummy area
If the back fits well but the tummy area looks loose, check the waistband. Is the waistband sitting at the correct place on the waist? If it is, you will need to shorten the crotch rise.
Check for a level waistband
Ideally you want the waistband to sit level to the floor, but most plus-size bodies have tummies and bums that will tilt the waistband while still being well-fitted. What you want to check is that the waistband sits at the level of the body that it is supposed to. So, at the front, does it sit at the natural waist? Is it comfortable on your stomach and is not pulling? At the back, does it sit above your bum at the natural waist? Is there excess fabric at the top of your bum indicating that you need a swayback adjustment? Is the waistband pulling down onto your bum indicating that you need a longer back crotch length?
The waistband and crotch are the two areas that are most affected by an ill-fitting jumpsuit.
Make the changes to the pattern pieces
Once you have assessed the fit of your first muslin, transfer those alterations to the paper pattern pieces and make a second muslin. Depending on how well your first attempt fitted, you could possibly make this one a wearable muslin, but I would still err on the side of caution and make it with fitting in mind. Choose shorts length, sleeveless etc. and use inexpensive fabric.
Second fitting
If you’ve been lucky, you’ll have nailed the adjustments and got a good fit. If this is you, pat yourself on the back and move on to your final garment. For most of us, this second fitting will reveal further tweaks and adjustments to get a perfect fit.
Did you eyeball the additional length you needed to add and now want an extra ¼” in the body? Is the seat still baggy and could do with another 1” taken out? Do it now. Because as much of a hassle as it feels to go back to the pattern pieces and make more adjustments to them and add more sticky tape, it will feel like a lot more hassle to cut and sew a beautiful jumpsuit that you end up never wearing because it’s not quite as comfortable as you would like it to be.
For this tutorial I used the Sunday Romper from Love Notions. This is a loose-fitting wide leg knit jumpsuit and is a good beginner jumpsuit pattern to try. Woven fabrics can be trickier to fit than knit fabrics and are best attempted once you feel confident that you can identify fit issues and you’re familiar with sewing terminology.
TIP: If you would like a very roomy neckhole for your jumpsuit, try my Chorus Romper Hack, which takes the bottom half of the Sunday Romper and mashes it with the draped cowl neckline of the Love Notions Chorus Top and Dress.
I’d love to see your jumpsuits, so use the hashtag #inclusivesewing when you post to Instagram, TikTok, Facebook or Pinterest and give me a wave. Alternatively, if you have fitting questions join my Facebook group and post your question there for fitting advice.