How to get a trouser pattern that fits.
Sewing,  Tailoring,  Tutorials

The quest for the well-fitting trousers – what I have learned

How to get a trouser pattern that fits? Sewing trousers is not really difficult. The difficulties come when you try to get them to fit. I have tried dozens of patterns and still the fit issues have persisted. My goal for this year has been to learn to make a good fitting pair of trousers and I think I have finally succeeded. Now I can share what I have learned.

First I will tell about all the patterns I have tried. Then I show you how to replicate your old pair of trousers that fit and how to adjust the pattern to get the perfect fit. I will also show some tricks that are not very widely known, so read forward!

The trouser patterns I have tried this year

Now you’ll see the truth about how much I haven’t actually published this year! I managed to find some photos of the not-so-well-succeeded trousers I have made.

  • Sew Over It Ultimate Trousers

I made a blog post about trying to get them to fit. At this time I didn’t know about the importance of the grainline which is the main reason my attempt failed. Also the pattern wasn’t really made for my body and there were numerous fit issues. Most of them stem from the fact that the whole pattern is drafted in a wrong angle for me. I am sure this pattern works for many people but not for me.

Sew Over It Ultimate trousers.

  • Sew Over It Carrie Trousers

These were a complete disaster – so much in fact that I didn’t even post them. You could think that this kind of loose fitting pants would be a piece of cake. Not! Basically the issues I had with the Ultimate Trousers showed much worse when there was much more fabric to show the fit issues. These pants formed horrible creases towards my crotch and were super unflattering on me.

Sew Over It Carrie trousers.

  • Style Arc: Claudia pants

My sewing guru Michele suggested these. I managed to make a pair of capris after about four or five toiles. This pattern would work better for a person with a flatter bum. They still tend to pull a bit across my hips.

Vogue Donna Karan collection V1440 blouse from the front. And my Claudia pants made into capris.

  • Vogue #1440

These were a leggings pattern. Unfortunately I made a size too big and was too lazy to fix them. I may fix them later if I manage to locate them…

  • Simplicity 3688

This is a 1940s retro pattern. This was a pair that gave me some hope to have a pair of fitting trousers since they actually fit pretty well. The waist became a little tight, though and I could have perhaps taken in a bit from the hips. In any case, they basically looked right with no pulling. The retro look, however, is not what I’m after. I did consider going forward and drafting this pattern into a pants sloper for me…

Simplicity 3688 1940s retro trousers.

  • Named Tyyni pants

I tried a pair of Tyyni pants when visiting Named studio-shop in the autumn. They fitted quite well and I bought the pattern. However, when I made my first toile, I was disappointed. They were super baggy and unflattering and needed a huge amount of work. I threw my toile away since I was so far from a well fitting pair that if I ever wanted one, I should start by comparing the pattern to a well fitting sloper before doing anything else:

After all these tries I knew I could make a pair that fits but I was not sure if any commercially available pattern would really work. There just is not a trouser pattern that would fit any body and thus trying different patterns is a bit hit-and-miss. Then I tried a pair of linen trousers I had found from a flea market and which actually fitted quite well. If I could just replicate them…

Replicating an old pair of trousers

Ok. Here are the linen trousers that fit me. You see how they hug my hips and that there are no weird creases radiating from my crotch. There are no front darts and two back darts, one on each side. (There is also a white lining that makes me look like I’m wearing giant granny panties… You just can’t have everything!) These trousers do not have any stretch, so that is useful since I want my sloper to work for many kinds of fabrics.

So what I did was to lay the pair on a big sheet of pattern paper. I used some fabric weights to hold the trousers in place. This is essential, since in order to draw the pattern, I have to keep moving the edges of the trouser pattern piece I am working on. The center front and back seam and the crotch curve are a bit challenging but they can be done. Here is a little video clip on how to proceed:

I draw my pattern using 15 mm seam allowance. You could also draw the pattern without any seam allowance, but since you have to fold the edges of the fabric back and forth I feel that is easier if my drawing line is a bit further away from the seam line.

Forget the waistband since that can be added later. You will be able to mark the back dart by approaching the dart position separately from both sides and keeping the fabric flat while you are drawing. Mark also the dart point on the pattern. Finally mark the grainline on both of your pattern pieces. This is important!

Toiling, toiling, toiling…

Make your toile out of cheap fabric that has approximately the same thickness as your trouser fabric you plan on using. I have been using the unbleached Ikea cotton and that works fine. One of my friends uses gingham that actually is a very good choice since the gingham pattern shows clearly where the grainline is twisted.


The importance of grain

Always and I mean always mark the grainline on your trouser toile. When you have the grainline visible it is possible to determine the cause of folds and creases that are due to twisted grainline. And yes, your grainline can get twisted even if you cut the trousers perfectly on grain. This happens when the shape of the pattern doesn’t properly match the shape of your leg.

Millimetres matter

Trousers don’t really have much ease. Tiny adjustments have a big effect. Moving a seam for 5 mm is a big change and has a profound effect on how the garment sits on you. This means that you have to cut your pattern accurately. If you don’t have a pattern that has seam allowances included, you have to measure and draw the seam allowances on your fabric (or the pattern) before cutting trousers.

Making and Fitting the toile

You can make your toile higher than what your finished trousers will be. Make your seam allowances big. 15 mm is a minimum, but I recommend to add even 4 cm to the side seams since you can always chop that extra off after you have adjusted the width.

Adjust your sewing machine to the longest stitch length. You can also reduce the thread tension to be able to rip the seams easily. Sew the trousers up but don’t sew the darts, yet.

Trouser toiles.
Some of my trouser toiles. These are from the time I was trying the Claudia pants by Style Arc, but the idea is the same…


The Closet Case patters has a great post about how to fit jeans. It basically lists most of the things that cause fitting issues. However, it’s best to tackle one issue at the time. Don’t expect the first toile to work all the way to the end. Some issues cannot be fixed in one go.

Start by fitting the waist so that the trousers stay up. (Otherwise tackling the crotch problems don’t really matter!) Pin the darts so that the waist has the right length. Take away the extra fabric at the side seams if there are any or let out the side seams if the trousers feel too tight. Don’t trim the seam allowances, yet. Then ask a friend to pin the darts to fit your body. Sometimes the darts need to be longer or shorter than what the pattern suggests or even be left out completely. Sew the darts.

Now, look at the grainline. It should be completely vertical. It if pulls to one side it means that that side needs more fabric. Look at the image above. You can easily see that the trouser toile in question needs more fabric at my upper thigh since the grainline pulls to the side. You can also check this by opening up the seam at the point where the grainline is pulling. The grainline should correct itself and a gap should be formed. Also, the side seams should be vertical. Treat them like grain lines, if they are pulling in one direction or another, you will need to add more fabric to that side.

The next thing to fit is the crotch. These adjustments are a bit tricky to explain since I have fitted pants only on me. What do the trousers look? What do they feel like? Is there fabric bunching up somewhere. Do the trousers feel tight at some point. Pay attention to wrinkling. Wrinkles are due to two different things. Either you have too much fabric that is bunching up, or then the wrinkles are formed because the fabric is pulling towards a place where there isn’t enough fabric. Try to determine which of the two things is causing the problem. The grainline is your guide. If the grainline is straight, you don’t have pulling of the fabric.

The thing that seems to be (sort of) missing in the grain line studios list is how to make room for a larger “derriere”. You can see in the pictures above how the center back seam is pulling up. What you will also notice, if you have this issue, that the trousers don’t “feel right”. They slide down and wrinkles are formed at the side seams since the fabric is pulling towards the center back. If you crouch down the crotch moves forward in an awkward way and the trousers slide down from the back. For me the low butt adjustment doesn’t really fix the issue. What I do instead is what my sewing teacher Michele calls “scooping out the back”:

Getting the trouser pattern that fits: Scooping out the back.

I think the image above is quite self-explanatory. The original pattern is black and the red line is the new center back line. Doing this will make room for your bum even when it means that you are actually taking out fabric! However, as a result the hip circumference gets smaller so you will have to compensate by letting out the side seams. After doing this you will really feel the difference!

Reducing the back thigh looseness

This next trick is from Kenneth King and my sewing teacher Michele taught it to me. This needs to be done only after the crotch fits and the width of the trousers is right. With dress pants that are wide you don’t do this since the trousers should hang down from the buttocks. Nowadays, however, most of the trousers are tight fitted and the extra fabric at the back of the thigh looks ugly.

So, what do you do with the extra fabric? How to get rid of it? If you just take out the side seams the front tight gets too tight and the side seams start pulling forward. What you need to do is so called fish-eye adjustment.

Unless you are a yoga master it is very hard to do the next thing by yourself. (I have managed it by twisting and pinning and then fixing the pins properly after taking out the trousers.) If you have friend that can help you, you could use her/him now!

Form a vertical pleat that starts somewhere below your bum and gets wider at the middle of your back thigh and finally tapers into nothing above your knee. This should take out the extra fabric. (The pleat is just for measurement purposes. There will be no weird pleats at your final trousers!) Mark this pleat on your fabric or pattern that you are using:

Getting the trouser pattern that fits: A fish-eye dart.

The fish-eye pleat should be on the grainline. Now draw horizontal guide lines and transfer each side of the fish eye pleat to the corresponding side seam. This means that you are taking the excess fabric out only from the back piece.

After doing this adjustment the excess fabric at the back of your thigh is gone!

Getting rid of small horizontal front creases

I would not bother with these in the toile stage. You can fix these in the final pair by curving the top edge of the trouser front piece. This pulls the fabric up and smoothes the creases.

Finishing the sloper

Ok. Now you have a trouser pattern that fits. Now take a permanent pen and mark the seam and dart positions. Determine where you want the upper edge of your trousers to be and mark the waistline on your toile. Add the seam allowance, too. You can also mark the preferred length of your trousers. In practice, it’s always best to add a bit extra length to any pair of trousers you are making. It is easy to chop of of after you have tried the trousers on with the shoes you are planning to wear with them.

Now you can take your toile apart and use it as your pattern!


Facings and the waistband

Trace the top edge from your toile to make the facings. It you are making a side zipper trousers it’s best to cut the facings on fold, so you need to leave out the seam allowances from the centre front and back. Join the dart edges together along the dart lines when you are tracing the pattern for the back facing.

If you want to have a proper waistband, you can use the pattern for the facings to make it. Just remove the amount of facing from the top of of your trouser pattern and replace that with your facing. Be careful with the seam allowances!

Creasing – why it matters

I think many of us have forgot everything about creasing because we tend to wear jeans so much. The dress pants need creasing in order to look sharp. The creases make especially the back part of the trousers fall nicely toward the floor.

Preventing stretched knees

Just a trick I read about on a tailoring site that works for wool. Use damp press cloth and iron and stretch the middle part of the fabric of the front piece from the knee down while you press. After the iron work the center line of the trousers should be about 6 mm longer than the sides. Straighten the bottom edge by cutting out the extra. Now you have pre-stretched the fabric so that it shouldn’t stretch so much in use!

My next goals

My quest for well fitting trousers hasn’t ended here. Now that I have a trouser pattern that fits I will use it to make different kinds of trousers from narrow modern fitting trousers to jeans. I will also add different pockets and pleats and experiment with details. I can combine my sloper with commercial patterns to be able to add different designs without compromising the fit.

Follow my blog to see my progress and join me with this quest! In the next post I will show you my changes to the sloper to make a narrower pair of trousers.

Please comment below and tell me if this post helped you and share it with your friends on social media!

Happy sewing!



I am a mother of two. I sew, knit and create and blog about it.


  • Kris

    Wow, what a great, detailed post! The right inseam of every close-fitting pant pulls to the front on me, and I guess I must need more room for my right quad based on what I learned here. And thanks for specifying that you do not actually sew the fish eye dart. For the longest time I thought there were sewists walking around with odd darts under their bums!

    • kk

      So glad you find it useful! Yeah, I thought along the same lines, so I wanted to specify. If you make the correction and get the inseam to work better, tell me! I’d be interested in knowing how it worked out!

  • Lisa Emery

    Thank you for taking the tome to share your findings! I am a 57 year old sewing professional, and made my first pants in 6th grade ( two pairs of striped, bell bottomed, hip huggers! ). I am still learning how to fit my own pants. I don’t have the same figure as back when I was 10 so it gets harder all the time. I actually absorbed a little new info. My best pair, which is very comfortable, are made from a copied “pretty good fit” pair. As long as I can manage to not see my back view they are wonderful. I am in the process of tweaking the seat on the pattern to try to achieve a more flattering look in the back.( I have to think of what others have to look at!) I had purchased a Fit For Art pattern but decided that this copied pattern is just SO CLOSE! Thanks for the encouragement and tips.

    • kk

      Thank you! I know the problem of changing figure! I used to have a pretty well fitting trouser pattern (although to be honest I did not know as much about the fit back then). Then I gained weight and was frustrated since it didn’t fit anymore. Good luck with your fitting project! It surely takes time and patience and a lot of spare fabric. I have made numerous attempts where I ditched the toiling stage too early and my trousers had to go straight to the bin since they were too small. Now that I bought a whole bolt of cheap Ikea cotton I find it easier to make toiles since I always have cheap fabric available.

  • Liz

    This is so brilliant. I have tried for years with hit-and-miss adjustments to patterns, but the fish-eye adjustment is the only one that works if you have thin thighs. Thank you so much Katja!

  • Leena Mannsåker

    Hei Katja! Kiitos näistä ohjeista, todella hyödyllisiä. Olen juuri saanut valmiiksi Named-kirjan Palo-farkut, jotka ompelin secondhand smokkihousuista ja liituraitahameesta, mutta nyt otan prototyypin esiin uudestaan ja tarkistan ja korjaan lankasuorat ja takamuksen väljyyden, ja piirrän sitten oman housujen peruskaavani!

    Haluan myös kehua sivujesi ammattimaista graafista tasoa, todella korkea.

    Terveiset Oslosta, kurssikaveriltasi Ompelinossa.

    • kk

      Kiitos! Housuissa kyllä riittää haastetta! Lankasuora on kyllä sellainen asia, että sen vinous aiheuttaa kaikenlaista kummallista ruttua ja laskosta. Silti aina kankaan vaihtuessa eteen voi tulla yllättäviä ongelmia, kun eri kankaat joustavat eri lailla eri suuntiin. Yläosa on siksi paljon helpompi.

      • Leena Mannsåker

        Nyt juuri raivasin ompelutarpeet pois piirrettyäni peruskaavan kolmesti (mittausvirheitä ja sekoilua) ja ommeltuani kaksi protoa. Seuraavat housut ompelen Fretex-löydöstä, 150×250-senttinen Ikean verho harmaata tukevaa lankavärjättyä puuvillaa, €15,-.ei ole vaaraa, että pilaan kalliin kankaan. Haasteita kyllä tulee, Ratkomaveitsi alkaa olla tylsä, Onneksi youtubesta löytyy videoita, jotka monesti täydentävät toisiaan. Näma¨sinun ohjeesi ovat kyllä ykkössijalla.

  • Judy Spivak

    Great article. However, I must be having a blank moment! With the fish-eye dart, I don’t get it! Are you supposed to add the dart width to side seams, then ‘close’ the dart , then cut the new leg pattern? Not sure how that changes the problem? Also your photo of back view of purple pants with crease lines radiating upwards & out- what causes those lines?

    • kk

      No, you divide the dart width between side seams and remove the width of the dart from the sides. Then you can forget the initial dart.

      With the purple pants… I didn’t keep those pants but it looks like a grainline problem to me. Now that I have more experience, I’d draw a grainline to my mock-up pants and see if it pulls. The grainline drawn to the middle of a trouser leg pattern should be vertical. Pulling means that you need to add more fabric to that direction. You could also say that the angle of the trouser leg is wrong to me. As these trousers are narrow they need to fit really well. With wider-legged trousers there’s always more room for error.

  • Fanfreluche

    I only just discovered your article. It is great. I have made several attempts for sewing trousers in the past and despite a load of adjustments (even with my sewing teacher at the time) I did not get a satisfactory result. Your article helps me to understand better where the problems are. I’ll do another test. Thanks a lot for this comprehensive compilation.

  • Jan Brown

    Hi. Like previous responders, I too have only just found your post on pininterest. The perfect trousers fit has always alluded me, despite buying books and attending talks. I do, however, have shop bought trousers that fit, so will try making a pattern from them.
    The fish-eye dart explanation was helpful too!
    Best wishes, Jan

  • Catherine Kelly

    I am working on my first pair of trousers. This is the most helpful advice I have found. So many great tips. Thank you!

  • Yvonne Dickson

    Great informative My problem is a thick waist and a flat low bum and very long thin legs There’s always bagginess either under the bum or behind the knees I think the knee bit can be fixed by making the front crotch a bit longer but I can’t seem to fix both Maybe a fish eye dart about crotch level might help Thank you

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