Knitting Decrease & Increase Calculator

The arithmetic is two divisions. Total shaping = start stitches − end stitches (96 to 72 is 24 decreases). Spacing = rows ÷ total: 36 rows ÷ 24 decreases = a decrease every 1.5 rows — which in practice means alternating “decrease every row” and “decrease every other row”, or clustering the decreases where the pattern reads best. When the spacing is a clean whole number — 48 rows ÷ 24 = every 2nd row — the shaping is perfectly even.

Where the decreases go is a style choice the calculator lets you pick. Evenly across the row suits circular yokes and hat crowns: the instruction “(k N, k2tog) × M” spaces M decreases uniformly. At each end suits flat pieces with visible edges — raglans, sleeve caps, neck shaping — where “k1, ssk, work to last 3, k2tog, k1” keeps a one-stitch selvedge and a clean decrease line you can seam against. Edge shaping is always paired: each shaping row takes one stitch from each end, so both edges slope on the same schedule — 2 stitches per shaping row, half as many shaping rows.

Run the same arithmetic the other way: stitches per increase = current stitches ÷ increases. To go from 72 to 96 stitches in one row (24 increases), 72 ÷ 24 = 3, so the instruction is k2, m1, (k3, m1) × 23, k1 — the first and last repeats are split so every m1 lifts a strand between two existing stitches instead of falling off the end of the row. Enter 72 now, 96 wanted and 1 row to get it. Spread the same 24 increases over 48 rows instead and the calculator places one every second row; switch to each-end placement and it becomes 12 rows of “k1, m1, k to last 1, m1, k1”, one every fourth row — the classic sleeve increase from cuff to upper arm.

A sleeve needs to go from 96 stitches at the underarm to 72 at the cuff over 36 rows. Total: 24 decreases. Spacing: 36 ÷ 24 = 1.5 rows between decreases, so the calculator alternates gaps of one and two rows: decrease on rows 1, 3, 4, 6, 7, 9, and continue that spacing through row 36. The other 12 rows are worked even throughout the section. Those 24 single decreases land on exactly 72 stitches at the cuff. Switch to each end and the same 24 decreases become 12 paired rows — “k1, ssk, k to last 3, k2tog, k1” on rows 1, 4, 7 … 34, one every third row — so the two edges stay mirror images. The row-by-row table shows each shaping row’s instruction and the running stitch count, so you can mark the pattern before you start.

For a rapid-shaping example, enter start 96, end 8, rows 22 with even placement. The 88 decreases are spread across all 22 rows — four per row, beginning with “(k22, k2tog) × 4”. A pattern that calls for eight decreases every other round needs that specific round schedule; the calculator distributes the requested total across the full section rather than selecting a hat construction for you.