How To Adjust the Length on a Sewing Pattern

This is just about the easiest pattern alteration to do!

You’ve probably noticed, many patterns have horizontal length adjustment lines marked on them to show where to alter the length. I don’t do that on all of my patterns, I prefer a cleaner look. It’s so easy to get in a muddle with too many lines everywhere and so simple to mark any length adjustments only if you need them. This straight forward tutorial will show you how simple it is to lengthen or shorten a sewing pattern, to help achieve a great fit.

TOOLS

• Your pattern (or copy of your pattern if you don’t want to alter your original)
• ruler
• pencil
• tape
• paper

Things to be aware of

• If you are unsure of how much length to add/reduce or even if you need to adjust the length, make a toile first. The silhouette and ease in a garment can make a difference to how long it should be.
• If you are doing lots of alterations to your pattern, do any length adjustments first.
• Keep the grainline or “place to fold line” IN A STRAIGHT LINE, do not allow them to stagger.
• The Chain Effect: when altering one pattern piece, also alter the corresponding pattern piece in the same way and remember to check they still fit together after your alteration. It is very annoying to end up with the front skirt longer than your back skirt!
• A toile is always your friend if you’ve done lots of (any) alterations!

Step 1

Once you’ve made a toile, you’ll know how much and where you need to add or subtract length to your garment. You can just change the bodice length, or a skirt length or the sleeve, or all 3!

Draw an adjustment line horizontally across your pattern at a right angle to the grainline or to the “place to a fold line”

On a bodice: mark the line above the waist line but below a bust dart, and straight through any waist darts.

On a skirt (or skirt portion of a dress) below the hip line, but avoid any pocket details – no point making life complicated!

On a sleeve: half way along the underarm seam, unless it’s a fitted sleeve or has an elbow dart, then divide between two lines. (See “Good to Know” at the end)

Step 2

Lengthen a pattern

Cut along the adjustment lines and separate the pattern piece.

Place a piece of paper behind your pattern and tape the top portion of your pattern to it.

Extend the grain line. Draw a line parallel to the your adjustment line the amount you need to lengthen the pattern by. Tape the lower portion of your pattern to the new line, matching up the grainline. Re-draw the seam lines so that they match up again, these may need to be curved or may be straight depending on your pattern piece. It’s quite usual to need to blend the new lines together, adding a bit to one and taking a bit off the other.

Shorten a pattern

Cut along the adjustment lines.

Place a piece of paper behind your pattern and tape the top portion of your pattern to it. On your pattern, draw a line parallel to the adjustment line the amount the pattern is to be shortened. Overlapping your pattern pieces, tape the lower portion of the pattern to the new line, matching up the grainlines. Re-draw the the seam lines so they match up again, in the same way as lengthening a pattern.

Step 3

Check your pattern pieces still fit together before cutting out your garment. Toile again if you need to!

Good to Know

The Maria Apron: lengthen the straps

This is a great method to use if you need to alter the length of the straps of The Maria Apron too. Be sure to keep the grainline aligned as before, but you can just chop through the strap, spread the pattern the required amount and re-draw the edges with a straight line – all without changing the length of the angled edge that attaches to your apron! You will need to do exactly the same alteration to both the TOP and UNDER straps.

Changing the length by a larger amount

If you are lengthening or shortening a sewing pattern by a larger amount, you can spread the amount between 2 lines

On a bodice, for example, take the amount needed to lengthen and place half above the bust dart, and half below the dart, this will of course lower the bust dart a little, so be sure you want it lower!

On a skirt, especially a maxi skirt style, half could go through the skirt in two places, this will lengthen the skirt and keep the hem circumference the same as the original. Alternatively, use one adjustment line and extra length could be added straight to the bottom of the hem, but the hem circumference will get bigger.

For a fitted sleeve: Spread the amount between two lines one above and one below the elbow/elbow dart.

Now, do I always use this method for changing the length of every pattern?

I’m 5’2″ so it’s always shorten, shorten, shorten.

NOPE, I don’t! If it’s only a little bit, or a boxy shape I’ll just chop it off/add the extra on to the bottom of the pattern. That works just fine too in some cases.

I hope you found this pattern alteration tutorial useful, and now can confidently alter the length of your sewing patterns.