Pants Pattern Adjustments : How To Lengthen or Shorten Pant Legs

Getting the length right is one of the easiest adjustments you can make to a pants or shorts pattern.

We’re all proportioned differently, even when we’re the same height. You might need a little more or less length through the thigh, the lower leg, or both.

For pants, where you want your finished hem to sit can also depend on the style of the pants and the shoes you plan to wear.

WHERE TO ADJUST

If your pattern includes lengthen/shorten lines, use these rather than simply adding or removing length at the hem. This helps keep the intended shape and proportions of the leg.

Pants will often have two adjustment lines:

• an upper leg adjustment line, between the crotch & knee
• a lower leg adjustment line, between the knee & hem

Where you make your adjustment depends on where you need the extra or reduced length.

If you need the adjustment mainly through your thigh, use the upper line. If it’s through your lower leg, use the lower line. If you need quite a bit of length added or removed overall, you can divide the adjustment between both lines.

For shorts, use the upper adjustment line only.

If your pattern doesn’t include lengthen/shorten lines, you can easily add your own. For pants, add an upper adjustment line between the crotch & knee and a lower adjustment line between the knee & hem.

HOW DO I KNOW HOW MUCH TO ADD OR REMOVE?

Start with the finished garment measurements included in your pattern, if they’re available, and compare these with where you’d like the finished hem to sit on your body.

If finished measurements aren’t provided, you can measure the pattern itself. Measure along the stitching line rather than the cut edge, then subtract the hem allowance to work out the finished length.

If you’re trying to work out where you need the extra or reduced length, you can also compare your own measurements with the pattern. For example, measure yourself from crotch to knee and compare this with the same measurement along the stitching line of the pattern.

This can help you work out whether you need to make the adjustment through the upper leg, lower leg, or both.

And remember, finished length is ultimately up to you. Think about where you want the hem to sit and, for longer pants, the shoes you’re most likely to wear with them.

HOW TO LENGTHEN

1. Work out how much extra length you need and where you need to add it. For our example, let’s lengthen the pants by 5cm (2"), divided evenly between the two adjustment lines.

2. Cut straight across the pattern at both adjustment lines.

Place paper underneath each cut and spread the pattern pieces apart by half the total amount you want to add at each adjustment line. Keep the cut edges parallel so the extra length is added evenly across the leg. For our example, we’re adding 5cm (2") in total, so spread the pattern 2.5cm (1") at each adjustment line.

4. Tape everything in place.

5. Smooth out the side seam & inside leg seam if needed.

6. Repeat the same adjustment on both the front & back pattern pieces.

FOR SHORTS: Add the total amount of extra length at the upper adjustment line only.

FOR PANTS: If the side seams are relatively straight or vertical, you may be able to simply add the extra length at the hem instead. Just make sure this doesn’t change the intended shape of the leg.

HOW TO SHORTEN

1. Work out how much length you need to remove and where you need to remove it. For our example, let’s shorten the pants by 5cm (2"), divided evenly between the two adjustment lines.

2. Above each adjustment line, draw another line for the amount you want to remove at that point. For our example, we’re removing 5cm (2") in total, so draw a second line 2.5cm (1") above each adjustment line.

3. Fold the pattern along each adjustment line, bringing the fold up to meet the line you drew above. Tape the folds in place.

4. Smooth out the side seam & inside leg seam if needed.

5. Repeat the same adjustment on both the front & back pattern pieces.

FOR SHORTS: Remove the total amount of length at the upper adjustment line only.

FOR PANTS: If the side seams are relatively straight or vertical, you may be able to simply remove the extra length from the hem instead.

ONE LAST THING: CHECK YOUR HEM

After lengthening or shortening, you may need to smooth out the side seam or inside leg seam where you made the adjustment.

If you alter either of these seam lines, fold the hem allowance up before cutting your new seam line. This will prove the hem and make sure the edges line up correctly when the hem is folded into place.