To lengthen or shorten a bodice, cut the pattern along the lengthen/shorten line printed between the bottom of the armhole and the waist, then spread the pieces apart or overlap them by the amount you need and redraw the side seams and darts. Never add or remove the length at the hem of the bodice: the armhole, the bust point and the darts would all end up in the wrong place. The amount comes from one measurement, your back waist length from the bone at the nape of the neck to the waist, compared with the same length on the pattern.
How do you know a bodice is the wrong length?
Put on the toile or the garment and find your natural waist: tie a length of elastic around your middle and let it settle in the narrowest place, or bend sideways and see where you crease. Then look at the garment's waist.
- Too short: the waist seam or the end of the bodice sits above your waist. The garment pulls up, the skirt of a dress starts too high, and the bodice tugs toward the waist with diagonal folds from the bust down. Dart points may sit above your bust point.
- Too long: a horizontal fold of fabric collects above the waist, where the bodice has nowhere to go. The waist seam sits below your waist, and the darts may end below the bust.
A length problem shows all the way around; it is the same in front and in back. If the back is fine and only the front pulls up, the front needs more length over the bust, which is a full bust adjustment, not a bodice lengthening. If the back pools and the front is fine, read about the swayback adjustment.
Which measurement tells you how much to change?
You need two numbers from your body and two from the pattern:
- Back waist length: from the prominent bone at the base of the neck (bend your head forward to find it) straight down the spine to the waist elastic.
- Front waist length: from the shoulder seam at the neck, over the bust point, down to the waist elastic.
On the pattern, measure the same two lines between the stitching lines, from the neckline seam at the center back to the waist seam, and from the shoulder seam at the neck over the bust point to the waist. Leave out seam allowances and any hem. The pattern should be longer than your body by about 1 cm (3/8 in) on a fitted bodice, so the waist seam rests at the waist rather than cutting into it. The measurement guide shows where each line runs.
If your back waist length is 42 cm (16 1/2 in) and the pattern's is 40 cm (15 3/4 in), add 2 cm (3/4 in) plus the 1 cm of ease: 3 cm (1 1/8 in). If the front shows the same difference, the whole bodice is short. If the front differs by more than the back, lengthen the whole bodice by the back amount and give the extra front length to a bust adjustment.
Where exactly do you cut the pattern?
Most patterns print a double line marked "lengthen or shorten here", usually 5–8 cm (2–3 in) above the waist, below the armhole and below the point of the bust dart. If your pattern has none, draw one: a line square to the grainline, below the end of the armhole and below the bust point, where cutting disturbs the least.
For large changes, more than 4 cm (1 5/8 in), split the amount between two lines: one above the bust, around the middle of the armhole, and one below. That keeps the armhole depth and the bust point in proportion. People who are short-waisted often need the second line as well, because the armhole is sitting too low along with the waist.
Cut the same line on every piece that shares the length: front, back, side panels, facings, lining and any front band. Draw the line across all of them at the same height from the waist before you cut.
How do you lengthen a bodice step by step?
- Draw a line square to the grainline through the lengthen/shorten line and extend it over the seam allowances. Draw a second line parallel to the grainline across the cut, to keep the two halves aligned later.
- Cut along the horizontal line.
- Tape a strip of paper to the upper half, wide enough to take the extra length.
- Spread the lower half by the amount, 3 cm in our example, keeping the vertical guideline straight on both pieces so the halves do not slide sideways. Tape.
- Redraw the side seam as a straight or gently curved line across the gap. The two halves will show a jog; connect them from a point above the cut to a point below it.
- Redraw the darts. A waist dart runs through the gap: draw new legs from the dart point to the original dart ends at the waist, so the dart gets longer and stays the same width at the waist. A side bust dart above the cut is unaffected.
- Repeat on every other piece, with the same amount, and check the side seams against each other.
How do you shorten a bodice step by step?
Shortening is a tuck rather than a gap:
- Draw the lengthen/shorten line, and a second line parallel to it, above, at a distance equal to the amount to remove.
- Fold the pattern along the lower line and bring the fold up to meet the upper line. The folded tuck is half the amount deep and removes the full amount from the length.
- Tape the tuck flat and redraw the side seam and dart legs across the fold, as above.
The seams on either side of a tuck jog in the opposite direction from a spread, with the lower half pushed outward. True them the same way.
Tip: Fold the tuck on the pattern piece without cutting, and keep it taped. If you alter the amount later, release the tape and refold rather than tracing again.
What else has to match the new length?
- Facings and linings are cut from the same pieces and get the same change on the same line.
- A side zip that runs through the bodice gets longer or shorter by the same amount; check the length on the notions list.
- A waistband or skirt does not change; only its position on your body does.
- A dress without a waist seam, such as a shift, is adjusted at the same place, between the armhole and the waist level, and the hem is left alone. Blend the side seam across the cut over 10 cm (4 in) so no bump shows at the hip.
Cut a quick toile of the front and back and check that the waist seam sits on the elastic all around. Making a toile takes an hour and saves a dress.
Do you still need this with a made-to-measure pattern?
The lengthen/shorten line exists because a standard size assumes a standard height and waist position. A pattern drafted from your own measurements puts the waist where your back waist length says it is. With Sewly, changing a measurement in your profile redraws the bodice, so the adjustment happens before printing rather than on paper. The petite and tall adjustments post explains which lengths matter most if you are far from the average height, and why the waist position is the first of them.