Thread Theory

Welcome to the new era of menswear sewing. Go ahead and create something exceptional!

Tutorial: Grading between sizes for the Jedediah Pants


Yesterday Eadaoin posed the following question in our comments:

“Since this is a sew along :) , I have a question for you… My hubby has a waist of 39.7″-> size 40 but a seat of 42.5″ -> size 36. With the slash pockets, I can’t grade-in the hips or can I? What would you suggest! … Thanks”

I thought this was a good question because, with the Jedediah Shorts Sew-Along beginning tomorrow, I am sure quite a few people are considering ways to create the perfect custom size!  Evidence of this is Elena of Elena Knits‘ recent post on adding width to the thighs and knees in order to better suit her athletic partner.

In order to help Eadaoin and others with any grading they might choose to do, I’ve illustrated how I would approach grading from a size 40 waist to a size 36 seat.  What do you think of my approach?  Do you know of any better way to do this?  Click on the images to see them full size.  The red lines indicate where you should draw new lines using a curved ruler (or eyeballing a smooth curve).  After drawing these lines you can cut out the pattern using the size 40 waistband, the graded lines and then the size 36 legs.

Front and Pocket-01

Back and Yoke-01

I HIGHLY recommend doing a mock up of the pants if you choose to grade between sizes (or before you start to sew your fashion fabric regardless of if you have adjusted the pattern or not as you may find out that you would like to make some adjustments based on your mock-up!).  There are a few potential issues that could be created by grading the pants.  Here are some that I anticipate if your grading is quite extreme and a few suggestions on how to solve them:

1. The front pockets could gape a little too much: If you mock-up the pattern after doing your grading you will see if this is the case.  You can remove the excess fabric by creating a deeper seam allowance for the front of the pants at the waist seam and the side seam (flattening the front of the pants onto the pocket lining and facings).

2. The seat seam might not fit as well as it will the way the pattern was originally drafted: Grading between two sizes will change the curve of the seat seam.  If you are worried about opening the can of worms that adjusting a pant seat seam can be (ug!) then consider leaving the seat seam as is and only doing minimal grading along the side seams.  I know this isn’t the correct way to approach things but it is far less intimidating if this is your first time adjusting the fit of a pattern!  Only do this if you are grading up or down ONE size (meaning you only need a small adjustment).  If you DO need to grade the seat seam, try to keep the shape and length of the new curve as similar as possible to the old curve.

3. The thigh area might become too baggy or too tight:  To fix this, you will simply need to extend your grading down the leg further so that the shift between sizes is more gradual.  At the tight or baggy point, make sure to keep your graded line closest to the larger or smaller size accordingly.

If all of this has got you a little overwhelmed, consider buying a cheaper pants fabric and just sewing them up in the closest waistband size for the sew-along – even if they’re not perfect, they will be a good start and will likely fit as well as RTW pants do.  From that point on you will feel comfortable with the sewing process and more familiar with the pattern so you will be ready to begin your custom fit adjustments for the next pair!  Basically, what I am suggesting is – don’t freak yourself out and just let the sew-along pants be your wearable mock-up!


I hope this helps everyone prepare for the big day tomorrow!  I will post the first sew-along post in the morning so that you have all day to make time to cut out your fabric.

By the way, check out Andrea of Four Square Walls‘ not one but TWO pairs of Jedediah Shorts – they look wonderful!  I love the tobacco colored twill she’s used for her second pair!

Jedediah Pants Thread Theory 7

13 thoughts on “Tutorial: Grading between sizes for the Jedediah Pants

  1. Thanks so much for this tutorial. It’s very helpful!! I know this comment is years later from the posting, but I’m hoping you’ll see it. 🙂 I graded from a size 38 hips to a size 40 waist. Do we need to modify the Pocket Facing pieces too once we’ve graded? Thank you.

  2. Hello. I’ve made a mock up of the pants and found that it’s a bit tight around the crotch/rear area. After looking at this tutorial and and, I’ve decided to grade from a 30 waist to a 32 seat and legs.

    I had a question regarding how you graded the Pocket Lining piece. The piece is graded on the right side, but not the left. (actually the other way around because of the reverse image) Shouldn’t there be another grading either on the opposite side or on the top or bottom? Otherwise, when I go to cut it out, there will be a mismatch. Where should this grading occur?

    Thanks for the awesome pattern and tutorial 🙂

    • Good eye! I will have to fix that diagram, thanks for pointing out the error to me! Good luck with your alterations, it seems as though you are on the right track. If you need any help, feel free to email us (at with photos of the problem area and I will try to give you some fitting suggestions. 🙂

  3. slight edit: that should read 16″ calf….i’m spindly, not a triangle….

  4. Feel free to tell me to go to hell if this is too complicated, but…

    slight preface: i’m 6’4″, but with spindles for legs! (23″ thighs, 26″ calf)

    I notice on the pair of jebs that i knocked up (which by the way was a total pleasure thanks to these blogs :P) that the fit is generally fine -waist, yoke area of seat, even the fronts of the legs – but the back of the legs i could easily lose 2″ of fabric per leg…and perhaps an inch on the seat.

    Would this just be a case of chopping 2″ off of the outseam of the back leg pattern piece, blending it out about level with the pocket opening? or is it not that simple? :/

    • Hi Dan,
      No worries, I can try to help you figure this out – it is hard to come up with the ‘perfect’ solution when I can’t be there to see the fit of the pants on you, but, based on your description, here are a few tips to experiment with:

      First, check out Colette’s fitting guide for thin legs (i.e. The Thin Leg Adjustment): Scroll down to find the Thin Leg version. You’ll notice they make alterations to both the front and back pattern pieces. This is advisable because altering only the back piece will likely make your side seams fall too far back. It might be worth experimenting with adjusting only the back though if you have the fabric and patience for additional mock-ups!

      Secondly, if, after mocking up the first change you find you need to remove the excess fabric from the butt, you can do the “Flat Butt Adjustment” also explained in Colette’s Clover sew-along: Scroll down again to get to the relevant adjustment.

      We are on holiday away from home so I don’t have access to my fitting book. I’ll have a look at it when I get home to see if I want to revise my suggestions at all :P. Good luck! Ask any more questions you have throughout your sewing process!

      • I’ve had a look at my fitting book now that I’m home and I still prefer Colette’s “Flat Butt Adjustment” to the solution provided in the book I use. I think that both techniques will have the same effect for you anyways!

  5. Thank you so much for this! Brilliant! Feel a bit bad, especially after such a super and illustrated tute, but I think I will cut a straight 40! This time at least and see how the pants hangs on the hubby! But at least I know what to do if they don’t fit – find another husband with a fuller behind. Sorted. Joking of course, will grade pattern accordingly…;)

  6. Thank you for this tutorial! 😀

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