Eric Banisadr my blog

How to Alter Pants

I got my wish: when I showed up to Moises, Gomez, and Associates, Carlos was officially out of curtains to alter. Instead, he had two pairs of pants laid out on the table.

    “We need to make these pants the same size as those.”

    “Sure, how?”

My Step-by-step Guide to Altering Pants

Carlos told me all of this, bit by bit, as we started to adjust the pair of pants he planned for me to work on today. However, the process is quite in-depth, and I’d definitely forget it if I didn’t write it down. So, I wrote it down. The specific alterations we’re doing are tapering the legs, and hemming the pants.


When measuring a set of pants (not pinning it in place on a person) you’ll need the following measurements:

Once you have the measurements, it’s time to take the pants apart and start marking. First, I had to open the top stitching on the seat, from the waistband to about three inches past the crotch. Then, I opened the seam at the crotch entirely. Usually, the hem needs to be opened too, but if the pants are significantly too long, then it can be cut off entirely. (Remember to leave extra fabric at the bottom for the new hem, though.)

Once the requisite seams are opened, turn the pants inside out, and start marking the front panel as follows:

  1. Measure the length of the inseam, mark the bottom and the knee (half the inseam plus two inches up).
  2. Transfer the inseam and knee measurements across to the outside of the leg, by measuring up from the bottom.
  3. Figure out how much needs to come off each side of the legs, at the hem and mark there. (Remove one-fourth the difference in leg circumferences from both the inside and outside of both the front and back panels.)
  4. Repeat the same process for the knee measurements.
  5. Draw a straight line between the new knee and new hem seams.
  6. Extend the line a few inches past the hem, but at a wider angle. (If you taper the fabric past the fold of the hem, it won’t hang well when it’s folded up and stitched in place, since its diameter will be smaller than the one its stitched to.)
  7. Smoothly join the new side seam with the bottom of the pocket. Use a curved ruler, but don’t make the line too curvy.
  8. Pin the line you just drew in place, and then measure the thigh circumference. Adjust the pants so the outside is folded over on itself, and the front panel perfectly lines up with the thigh measurement. Mark the back panel (which should be sticking out behind the front panel now) at the thigh measurement. If you remove fabric from the front panel, it will likely cause the pants to hang incorrectly, and the excess of the fabric is almost always in the seat, so only take fabric from the back panel at the thighs.

After measuring everything, you’re ready to start sewing.


After measuring everything, start stitching certain seams together as follows:

  1. Sew each outseam together, keeping the legs flat.
  2. Sew the inseams together in one step, starting from the bottom of the right leg, and continuing to the bottom of the left leg. Don’t connect them at the crotch, but it’s fastest to do them this way.
  3. At this point, Carlos removed a small amount from the seat of the pants, in a curve. Maybe around an inch and a half at the widest part. I’m not sure exactly how this is done since it seems like he mostly eyeballed it.
  4. Stitch from the back to the front of the center seam.
  5. Overlock all the seams together, after cutting half an inch from each seam.

After everything’s closed up, press all the seams flat. Start with the legs, but make sure they line up with the way the seams are pressed already, in the parts you didn’t alter.


I haven’t actually done this part yet, so I won’t be able to write it in until after today….


Trim extra threads, press everything nicely and you’re done. That’s all there is to it. Most likely, I’m the only one who’ll ever need to refer to this guide, but if not, congrats; you successfully tapered and hemmed a pair of pants.