How to measure the inseam of jeans vs. pants guide

By Maurice Malone & Jack Matthews  Published March 20, 2020, Updated Feb. 17, 2023

We start with a 12-second video that shows how to measure the inseam of a pair of jeans. This video serves as a quick reference for those who are unsure how to measure their jeans.

To learn how to measure the inseam of traditional pants, read the sections that follow the video. There are also more detailed explanations and "how-tos" for jeans and pants that are sewn similarly to jeans.

Video: How to measure inseam on jeans quickly

The starting point of the measurement is determined by the crotch construction of the pants or jeans

One of the most common questions asked is how to measure the inseam on jeans and pants. When it comes to alteration services, tailors, and brands, not everyone measures the inseam in the same manner, especially when measuring jeans.

We begin by admitting that there is no single method for measuring the inseam. The truth is that it is entirely dependent on the construction of the pants or jeans you intend to measure.

Pants with only a seam line in the crotch are simple to explain. Begin measuring at the seam line. The seam line will be the center point between the two legs without any stitching to constrain the seam. After that, we explain the most commonly misunderstood measurement method for jeans and pants with a double-needle stitch line or flat-felled seams in the crotch.

Photo shows how to measure inseam on jeans by starting at the center of the flat-felled seam.

Does measuring start from the seam line, or between the two stitch lines?

The point of confusion begins with where to start the measurement in the crotch. Is it from the seam line (as we recommended in the past), or do we start from the center of the two stitch lines?

After some internal debate and experiments, we concluded that if the jeans or pants are constructed with flat-felled seams in the crotch (front and rear rise seams), the correct center of the inseam would be at the center of the double-needle stitch lines. The starting point would be as shown in the photo above.

In the past, like many, we figured the center point of the two sides of the pattern panels would be the seam line. This is not the case with flat-felled seam constructions. It is actually the center of the seam allowance.

In addition, when wearing jeans, the seam line is pulled up and sits horizontally in the crotch. A double stitched or flat-felled seam does not fall on the seamline at an angle.

The seam line would be the center point in the crotch if the jeans or pants have no top stitching and are constructed with the seam allowance split on each side. The seam line could also be the center point if constructed with an overlock with none, or a single-needle top stitch.

Here's where things get tricky. Some brands use an overlock construction at the front rise, with flat-felled rear seams. For aesthetic purposes, the seam lines are even in the crotch, although the exact inseam length of the rear and front sides is slightly different by a very small amount. In this case, do you measure the seam line, or between the stitch lines on the rear legs?

Photo shows how to measure inseam on jeans with a measuring tape from crotch to hem

The next step is to lay your pants flat on a large enough surface to accommodate the entire pair. When measuring the inseam of a pair of jeans, make sure to run your fingers along the seam and flatten any wrinkles you may come across. Doing this will ensure a precise measurement when using a flexible tape measure. This step applies to both pants and jeans. As a guide, refer to the image above.

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