How can a pair of jeans be made larger in the waist?

You have 2 options. The first option is to purchase the jeans to fit your waist and take them in to fit the legs. Second option is to have gussets installed in the waist to make it larger. Either way, I recommend having an experienced seamstress do the work for you. Most cleaners will be able to recommend one for you. Good luck.

I found this unique method interesting...and it worked for my needs.

https://m.youtube.com/watch?v=gsWB98uJPo4

There are some simple devi that will attach to your existing button to give you another button moved over maybe a inch if you only need a little extra room! Certainly probably the cheapest and less labor intensive way to solve the problem!

Here you go!

https://www.walmart.com/ip/Button-Pant-Extender-Value-3-pack-Adds-2-3-cms-Instantly-by-More-of-Me-to-Love/215236748?wmlspartner=wlpa&selectedSellerId=6078&adid=22222222227104896447&wl0=&wl1=g&wl2=t&wl3=233997250930&wl4=pla-386900857621&wl5=9031180&wl6=&wl7=&wl8=&wl9=pla&wl10=114227149&wl11=online&wl12=215236748&wl13=&veh=sem

https://www.amazon.com/dp/B0738MFGTY/ref=asc_df_B0738MFGTY5404811/?tag=hyprod-20&creative=395033&creativeASIN=B0738MFGTY&linkCode=df0&hvadid=216514968137&hvpos=1o1&hvnetw=g&hvrand=8152681269102606332&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9031180&hvtargid=pla-349441185800

https://www.pinterest.com/dougkenedy/waist-extender/

Any good fabric stores will have in stock too. I would look there first!

I've used 3 different methods to extend waistbands for actresses on stage. They only work If you will be wearing blouses that cover your waist Or Belts to cover the waist band, and you only need a little extra room. They are Not petty when finished. I apologize I've demonstrated these in person but don't have pictures or time to make a tutorial. 1.)You could make an extender. 2.) You could add the equivalent of an elastic gusset at both sides of the waist band, 3.) You could add a casing for elastic, or 4.) You can Google how to alter jeans for maternity wear as there are some great options available there that will work for those of us who aren't pregnant!

Option 1) If you only need a LITTLE extra waistband you could make an extender out of a triangle of two layers of denim and an interfacing Cut the top of the triangle 3 1/2 " wider than the additional pants waist you need. The point of the triangle should extend down from the top waist triangle edge's middle point to 2 inches below the top of the zipped zipper when the pants are on you. Stitch as you would a pillow using a 5/8" seam and leaving 2 inches along one edge of a side unsewn so,you can turn right side out. Slip stitch the hole you left for turning. Press flat. Top stitch if you desire. Put a button and button hole on the top edge and extend the bottom point of the triangle down as though it's a shirt tail under the zipper. Sew a button on the inside of the jeans waistband and near the edge of the waistband. Attach the extender's button so it may go through the jean's hole and the jean's button can go through the extender's hole.

Option 2) To add elastic gussets: Rip open the side seams near the belt and slit the waist band straight up the waist until you can pull the waist apart the amount you'll need added to the waist plus an inch this will only give you 1/4 inch for sewing so if you can pull further apart, do so. Measure the minimum width you need for each gusset. And cut your elastic at least 2 inches longer than you'll need. Lay the denim in a widening V over the widest blue or black elastic you can find (2 to 4 inches). Follow the following procedure on each side: Lay the denim in a widening V shape over the elastic and stitch by hand. Try jeans on carefully to insure fit. Adjust as necessary. Stitch over the denim's raw edge with a zig zag machine stitch through both elastic and denim. If you are a really good seamstress you can turn under the side seam part that is not the waist band, but lay the waistband flat and zig zag over it so you can maximize the fabric and avoid the discomfort of added bulk. Now Sew a straight stitch through the denim and elastic on the outside of the gusset. It is important to have this second row of stitching, especially in jeans as there will be a lot of stress on the seams. You can trim the elastic and place bias tape or seam tape over the raw edges if you want a finished look. This won't be pretty enough to wear without covering the waist, but it should be functional.

Option 3) If you absolutely do not need anything but the waistband expanded, you might add a casing. Slit the waist band at the side seams or center back. Ripping the waist band back far enough to stitch a casing (of knit or really stretchy denim) to hold an elastic strip the width of the waistband. Believe it or not, this is a much harder process than the earlier recommended fix to make look good.