Top-Down Raglan Sweater Calculator

How this works

A top-down raglan starts with a neck cast-on split into four sections — back, front, and two sleeves — separated by four raglan lines. Each "increase round" adds 2 stitches per raglan line (8 stitches per round, total). You keep doing increase rounds until you have enough stitches to separate the body from the sleeves.

Raglan math is over-determined: you have four constraints (neck, chest, yoke depth, section weights) interacting through one degree of freedom (how many increase rounds you do). Something has to give. Most calculators silently derive yoke depth from chest. We do the opposite: yoke depth is the load-bearing input, and we verify whether the resulting schedule actually lands at your chest target. If it doesn't, we say so — and suggest a yoke depth that would close.

What's the closure check?

At separation we add up the body: front + back + both underarm cast-ons. That's your actual chest — the two sleeves come off onto holders and are not part of it. We compare that total against your chest target (chest + ease) × stitch gauge.

• Closes — within 1" of target. You're good; cast on and go.
• Short — 1-2" below target. Sweater will be tighter than you wanted. Try a deeper yoke or accept negative ease.
• Past target — 1-2" above target. Sweater will be looser. Either accept the extra ease (intentional oversized look) or use a shallower yoke.
• Off target — more than 2" off. Something's wrong: gauge swatch probably needs re-measuring, or your yoke depth doesn't match this body and gauge. If your swatch gauge differs from the pattern's, run the numbers through the gauge converter first.

Underarm cast-on

At separation the sleeves come off onto holders and you cast on a few stitches at each underarm — roughly 1.5" for adults, 1" for children. That cast-on is the gusset that completes the chest: your finished chest is front + back + both underarm cast-ons, not the whole yoke.

Upper-arm width

This calculator uses a single increase rate for body and sleeves, so the upper-arm width follows from your inputs (neck split and yoke depth). If a sleeve reads too wide or too narrow, adjust the sleeve section weight to shift stitches between body and sleeve. Independent body and sleeve increase rates are a planned future addition.

How do I pick a yoke depth?

Yoke depth is the vertical distance from the cast-on edge (neckline) to where you split off the sleeves. A rule of thumb is chest × 0.18 — for a 36" chest, that's about 6.5". Use the "Estimate from chest" button if you don't have one in mind.

• 6-7" — typical for adult-sized fitted raglans.
• 7-9" — relaxed/oversized; gives more shoulder coverage.
• 5-6" — cropped or set-in-shoulder look; tighter at the underarm.
• 4-5" — child sizing or very fitted; check that closure still works.

Section weights — pullover vs cardigan

The four sections don't have to be equal quarters. Real garments distribute stitches unevenly to fit the body better — the same even-spacing logic that the decrease distribution calculator uses to space shaping across a row:

• 30 / 30 / 20 / 20 (default) — standard pullover. Back and front slightly wider than each sleeve.
• 35 / 30 / 17.5 / 17.5 — cardigan. Slightly wider back, slightly narrower fronts each (so they meet without overlap), narrower sleeves.
• 25 / 25 / 25 / 25 — equal quarters. Boxy fit; common in some children's patterns or quick-knit drop-shoulder styles.

The advanced section in the form lets you set custom weights. Back + Front + 2 × Sleeve must always sum to 100.

Why every-other-round increases?

Standard raglan cadence: increase on round 2, knit plain on round 3, increase on round 4, and so on. The plain rounds give the fabric room to lie flat instead of cupping sharply at the shoulder. Every-round increases (rare, used for unusually tight shoulders) compress the raglan line vertically — they're a future option, not the default.

Tips for accurate inputs

• Block your swatch before measuring gauge. Knit and unblocked measurements drift by 5-10% — that compounds quickly across 100+ stitches.
• Measure neck loosely — where the cast-on will sit, not the base of the throat. Pull the tape so it lies flat without compressing.
• Add ease deliberately. 2" of positive ease is the default fitted look. Negative ease (-2") for a snug ribbed top; 4-6" for cozy/oversized.
• Trust the closure check. If it says "severe", don't push through — remeasure your swatch or adjust an input. A 2"+ error becomes a sweater you won't wear.