Free guide

Short-row bust darts: adding bust room to a knitted sweater

Vintage patterns were written for one figure, shaped by the firm, structured underwear of the time. Knit the same fitted sweater today with a fuller bust and you'll often see the same thing: the width is fine, but the front hem rides up and the side seams pull forward.

That isn't a width problem. The front needs to be a little longer than the back, because it has further to travel. Short-row bust darts add that extra length only across the front, only where it's needed, and the seams still match.

They look fiddly written down. In practice they're a handful of turned rows, and once you've done one set you'll wonder why every pattern doesn't include them.

Do you need them?

You'll need a tape measure, a piece of string or narrow elastic, and ideally a friend. Wear the bra you'll wear under the sweater, because it changes the numbers.

Tie the string snugly round your ribcage, just under your bust, level all the way round.
Front: measure from the top of your shoulder, where a bra strap sits, down over the fullest part of your bust to the string.
Back: measure from the same shoulder point straight down your back to the string.
Subtract the back from the front.

If the difference is under about 2 in (5 cm), the stretch in the knitting will usually cope and you can skip the darts. Above that, they help, and the fitted designs of the 1940s and 1950s, with only a couple of inches of ease, benefit most. Roomy 1980s shapes need much less.

How much length to add

Tutorials don't all agree on this, so here are the common approaches, gentlest first:

Take 2 in (5 cm) off the difference for the stretch of the knitting, and add the rest. A 4 in difference gives a 2 in dart.
Use a simple scale: a 1 in (2.5 cm) deep dart for a difference of 2–3 in, and a 2 in (5 cm) dart for anything over 3 in.
Add the whole difference. This gives the most room.

If you're unsure, start gentler. Slightly too few short rows looks fine; too many leaves a pouch of spare fabric at the front.

The numbers you need

Before you start, write down:

Your row gauge (rows per inch) and stitch gauge (stitches per inch).
The dart depth you've chosen.
The front width at the bust, in stitches. Your pattern gives this.
The distance between your bust points. Measure straight across, from the fullest point of one side to the other.

Then:

Short rows: dart depth × rows per inch. Round to an even number. Half of them turn on each side.
The middle section, which you leave alone: the distance between your bust points plus 2 in, converted to stitches. The extra inch on each side stops the dart ending in a point right on the bust.
A margin at each side, also left alone: about 1 in, so the turns don't sit right in the side seam.
The dart width on each side: what's left. Front stitches, minus the middle section, minus both margins, divided by 2.
Spacing: spread the turns evenly across the dart width.

Working in centimetres? The method is just the same: use rows and stitches per cm, and 2.5 cm wherever it says 1 in.

A worked example

You're knitting the front of a fitted 1950s sweater in fingering (4-ply) yarn. Your gauge is 28 stitches and 36 rows to 4 in (10 cm), which is 7 stitches and 9 rows to 1 in. The front measures 21 in across at the bust, which is 147 stitches.

Your front measurement is 3½ in longer than your back, so you choose a 2 in (5 cm) dart.

Short rows: 2 in × 9 rows = 18 short rows, so 9 turns on each side.
Middle section: your bust points are 8 in apart. 8 + 2 = 10 in, which is 70 stitches.
Side margins: 1 in, which is 7 stitches each side.
Dart width: 147 − 70 − 14 = 63, and 63 ÷ 2 = 31½. Call it 31 stitches each side.
Spacing: 9 turns across 31 stitches leaves 8 gaps between turns. 31 ÷ 8 is just under 4, so turn 4 stitches further in each time. Rounding up puts the last turn a stitch inside the middle section, which is fine.

So the first turn on each side is 7 stitches from the edge, then 11, 15 and so on, up to 39. That leaves the shortest rows working across the middle 69 stitches, a fraction under 10 in. The rounding doesn't matter: these are guides, not exact science.

Working them in a bottom-up sweater

Most vintage sweaters are knitted from the hem up, so this is the usual way.

Where to start. Work the front as the pattern says until it reaches just under your bust. Holding it up against yourself, or trying it on with the stitches on a spare cable, is the easiest way to judge this. In a fitted sweater it's usually a little way above the end of the waist shaping. The darts go in before the armhole shaping begins.

The short rows, using the example above:

Short row 1 (RS): knit until 7 sts remain, turn.
Short row 2 (WS): purl until 7 sts remain, turn.
Short rows 3 and 4: work until 11 sts remain, turn.
Short rows 5 and 6: work until 15 sts remain, turn.
Carry on the same way, leaving 4 more stitches each time (19, 23, 27, 31, 35), until short rows 17 and 18 turn with 39 sts remaining. That's 9 turns on each side.
Next row (RS): starting from your last turn, knit to the end, closing the gaps as you pass them.
Next row (WS): purl to the end, closing the gaps on this side.

"Until 11 sts remain" means 11 stitches still waiting on the left needle.

Bottom-up, you work from the longest short row to the shortest. The darts slope up towards the bust, which is just where the extra length is needed.

Then carry on with the pattern.

Working them top-down

If your sweater is knitted from the neck down, turn the order round. Start at, or just below, the fullest part of your bust and work the shortest rows first, turning about 1 in outside each bust point. Make each pair of short rows longer than the last until the final turns are about 1 in from the side edges.

Which short-row method?

Any short-row method works. These two are the most common:

German short rows. Turn, slip the first stitch purlwise with the yarn in front, then pull the yarn up and over the needle so the stitch sits with both legs on the needle. When you come back to it, work both legs together as one stitch. Quick, and very neat in stockinette (stocking stitch).
Wrap and turn. Slip the next stitch, bring the yarn to the other side of the work, slip the stitch back and turn. When you come back, pick up the wrap and work it together with its stitch, so no little bar shows.

Whichever you choose, practise on your swatch first. In garter stitch the wraps hide in the ridges, so you don't need to pick them up.

Cardigans, stitch patterns and stripes

Cardigans. Each front gets its own dart, on the side-seam side only. The turns sit between the side margin and 1 in outside the bust point; the rows always run all the way to the front edge. Because the front edges end up a little longer, pick up the button bands evenly along the whole edge rather than counting rows.

Cables and lace. Plan the turns in plain stitches where you can. Some vintage designs have stockinette at the sides with the pattern in the middle, which suits darts perfectly. If the stitch pattern runs all the way across, swatch a few short rows in it first.

Rib. A sweater knitted all over in rib stretches a great deal, and often doesn't need darts at all.

Stripes, checks and colourwork. Short rows lift the centre of the front, so any horizontal lines will curve up over the bust. A stripe or two usually looks perfectly natural. A tight check or a two-colour pattern shows it more, so think about whether you'd rather have the extra length or the straight lines.

A note on width

Short rows add length. If the sweater fits your shoulders but is tight across the fullest part of the bust, that's width, and a different fix: extra stitches across the front only, increased below the bust and decreased again above it (sometimes called vertical darts). Front and back don't have to be the same width. Keeping the back as the pattern intends keeps the shoulders neat.

Many knitters with a fuller bust need both. Our plus-size vintage knitting guide covers width, armholes and sleeves.

Short rows in one of our patterns

Our patterns are written for your bust measurement, so the width is already right for your size. Darts are something you add, and they fit in neatly:

Measure lengths at the side edge, not down the middle. When the pattern says the front should now measure a certain length, check it at the side, where the darts add nothing. Your front and back side seams still match row for row.
Don't count the short rows as pattern rows. Note them separately, then carry on with the row numbers as written.
Pick up neckbands and front bands evenly along the edge, as the pattern says. The edge may have a few more rows than the pattern expects, and that's fine.

If you'd like a second pair of eyes on your numbers, email us at support@vintagetomodernknits.com with your pattern, size and measurements. A real knitter will help you work out where your darts go.

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Last updated 2026-10-12.