How To Take In The Crotch Seam on Pants

Updated: October 19, 2020

I just got an email from a reader whose husband’s pants are hanging too low in the crotch area and she wanted to know how to take in the crotch seam on pants.

It’s a very common problem.

I thought about how to show you with an actual pair of slacks, but I think you’ll catch the idea much better and faster with a diagram.

It’s a very easy alteration.

(By the way, if you need more room in the crotch area, be sure to read this post on How To Put in Gussets in Pants or Shirts.)

But back to this alteration…

Please read the entire post before you begin because it will be easier for you to visualize the alteration and because there are some details you need to know ahead of time.

First, figure out how much material needs to be taken in in the crotch area.

If you are making this alteration on your own pants, it’s easy to pinch up the fabric, pin it and measure that.

But, if you are working on pants for a customer, it would be awkward for you to pin up that area on your customer while they are wearing the pants, so have them do it before they get to your establishment.

Or, if they aren’t confident in doing that, you can do it for them by first having them try on the pants and you making a good estimate on how much needs to be taken up.

To do that, I pin up an amount and then have the customer try them on again and make adjustments from there if needed.

Once that amount is known, measure that amount and write it down. Remember that you are measuring on both sides of the pin. In other words, if you pin it at 1/2″, then the entire amount you are taking in is 1″.

Next, you are going to open up the crotch seam (this entire seam is called the crotch length and is also called the rise. It is the seam that runs from the waist in the front down the center front and up the backside to the back waist seam.) See diagram below.

9393, diagram of the crotch seam (or rise) in a pair of pants, taking in the crotch seam on a pair of pants

Think of it as the vertical seam where the crotch seam and the inseams intersect. The inseam is the seam that runs from the crotch, along the inner leg to the ankle area.

Open up the crotch seam (rise) at least twice the amount you’ll need to take in.

9396, a diagram of the rise and the crotch seam, taking in the crotch on a pair of pants

In other words, if you are taking in 2 inches total, then open up about 4 inches of the crotch seam.

Don’t open up the inseam though!

9395, diagram of an inseam, taking in the crotch seam on a pair of pants

Keep that inseam intact. You might find that some inseam stitches become loose. Just stitch those loose stitches back up and backstitch over them to keep them intact.

The alteration will be done on the inseam. (See diagram below)

Let’s say that you need to take up a total of two inches in the crotch. That means you’ll need to take in one half inch on each inner leg seam as illustrated in the diagram below. You have 2 backs (a right back to the pants and a left back (1/2″ + 1/2″ = 1″ total) and 2 fronts (1/2″ + 1/2″ = 1″ total). If you add the two fronts and the two backs you get a total of 2″ altogether.

You can see what the new seam will look like based on the dotted line in the diagram below:

diagram on how to take in the crotch seam on pants, 1361

(The diagram is only to show you what the pattern pieces would look like if they were sitting on the table). I want to show you the areas where you’ll sew on the front of your pants and the back of your pants. To review and clarify, you’ll only be opening the crotch seam (or rise) and only sewing the inseam on this alteration. If you think about it as you look at the diagram above, when you take off that excess on the inseam it will automatically shorten the crotch seam (rise) in the pant. It is also important to note that doing this alteration will not affect the length of the pants, as you might wonder about that.)

Now, once that crotch seam is open, put the front left leg and the back left leg together and stitch along your own dotted lines (based on the measurements you figured out for your own pants) being careful to taper the seam back to the original seam line down the leg, just like the dotted line represents.

Do the same with the right front leg and the right back leg.

Once you do that, the crotch seam is the exact measurement it needs to be.

(This may seem like a strange way to alter the crotch seam, but trust me, this works!)

Once you have stitched the new seams, along your own dotted lines, you can pin or baste the crotch seam closed and have the customer try on the pants if you (or they) are not sure of the fit. If this is your first time at this alteration, I would suggest you do this. After you’ve done it several times, you will gain alot of confidence in the process and being able to know how much fabric to take up.

That’s what alterations and sewing are all about. Once you learn the concept, practice, practice, practice! Many people are excellent sewists, but they just lack experience. If you want to, take two pieces of fabric and try this first. Once you’ve mastered the technique, you’ll be able to quickly do this alteration!

Once the fit is just right, you can be confident that you are ready to stitch the pants back up.

Now, stitch up the original crotch seam along the original seam line. You should be able to see the stitching marks from where the pants were originally sewn. Follow those stitching lines and stitch the pants back up.

You can trim the seam allowances if you need to, if there is too much bulk. I like to trim the excess, because it makes the seams lie flatter and it makes the pants more comfortable to wear.

That’s all there is to it!

As I’ve stated in other posts, if you have to alter those pants more than two or three sizes, you may not be able to take in all the fabric you need to, but this is going to help immensely!

Leave me a comment or a question at the bottom of this page if you need more clarification. Or send me an email with a photo of what you’re looking at so I can better answer your question! My email address is: