What is ease and how much should I add?

Ease is the difference between your body measurement and the finished garment. Zero to a couple of inches gives a fitted look, 4-6 inches gives a relaxed fit, and 8 or more gives an oversized fit. Add it on top of your actual chest measurement.

What sweater shape does this calculate?

It drafts a simple drop-shoulder pullover knit flat in two panels (front and back), the most beginner-friendly construction. Each panel is half the finished circumference, and the sleeves are tapered tubes worked from cuff to underarm.

How is the sleeve increase schedule worked out?

The tool finds the total stitches to add between cuff and upper arm, splits them into pairs (one increase each side), and spaces those pairs evenly across the sleeve rows. The result is an increase rate like one stitch each side every N rows.

Why are my cast-on numbers a bit different from a published pattern?

Published patterns add stitches for selvedges, seams, and specific stitch-pattern repeats, and may use a different construction. Use this as an accurate starting frame, then round to your stitch-pattern repeat and add edge stitches.

Can I use this for a yoke or raglan sweater?

The body cast-on and sleeve math still apply, but yoke and raglan constructions add their own shaping and decrease lines this tool does not draft. It is most directly accurate for drop-shoulder pullovers.

Knit Sweater Sizing Calculator

Draft a custom-fit pullover from your own gauge

Buying a pattern in your exact size is not always possible, and knitting to fit a real body often beats following standard sizing. This calculator turns your measurements and gauge into the concrete numbers you knit from: how many stitches to cast on for each panel, how many rows to work, and exactly how to shape the sleeves.

How it works

Everything starts from gauge, expressed as stitches and rows per unit:

stitches per unit = stitch gauge ÷ swatch length
rows per unit     = row gauge ÷ swatch length

For a drop-shoulder pullover knit flat, the front and back are each half the finished circumference:

finished chest = body chest + ease
panel cast-on  = (finished chest ÷ 2) × stitches per unit
body rows      = body length × rows per unit

The sleeve is a tapered tube. The tool finds the difference between the upper-arm and cuff stitch counts, divides it into increase pairs (one each side), and spaces them evenly across the sleeve rows:

total increase   = upper-arm sts − cuff sts
increase pairs   = total increase ÷ 2
increase every   = sleeve rows ÷ increase pairs   (rounded)

Tips and example

Gauge 20 sts / 28 rows over 4 in, chest 38 in, ease 2 in, body 24 in, sleeve 18 in, upper arm 13 in, cuff 8 in:

Stitches per inch = 5; rows per inch = 7
Panel cast-on = (40 ÷ 2) × 5 = 100 sts each for front and back
Body rows = 24 × 7 = 168 rows
Cuff = 8 × 5 = 40 sts, upper arm = 13 × 5 = 65 sts → add 25 sts → ~12 pairs → increase 1 st each side every ~10 rows, 12 times

Round panel cast-ons to your stitch-pattern repeat and add a stitch or two each side for seams. Always re-check your blocked gauge before casting on for real.