Sleeve Decrease Calculator
How often to decrease down a tapered sleeve.
Calculate the decrease frequency for a tapered sleeve from the upper arm and cuff stitch counts and the sleeve length in rows.
Decrease every nth row
every 10
12 decrease rounds
Work the leftover rows plain at the top of the sleeve before the shaping starts, not at the cuff. Finishing the decreases a little early is invisible; running out of rows before they are done is not.
How the Sleeve Decrease Calculator works
A sleeve taper is a spacing problem with a hard deadline: the decreases have to be finished by the time the sleeve reaches the cuff, and spread evenly enough that the line looks straight. Each decrease round removes two stitches, so the round count is fixed and the only free variable is how many rows sit between them.
Also known as: sleeve taper calculator · sleeve shaping calculator
How the number is derived
A sleeve taper removes two stitches per decrease round, one at each side of the underarm. So the number of decrease rounds is the stitches to lose divided by two, and the frequency is the sleeve length in rows divided by that.
The deadline is what makes it a real problem rather than a division. The decreases must be finished before the cuff, so the frequency has a hard upper bound, and a taper that is too aggressive for the length simply does not fit.
Any leftover rows go at the top of the sleeve, worked plain before the shaping starts. Putting them at the cuff end leaves an unshaped section right where the sleeve should be narrowest.
A worked example
Seventy-two stitches at the upper arm down to forty-eight at the cuff is 24 stitches, so twelve decrease rounds. Over a 120 row sleeve that is a decrease every tenth row, with no remainder.
Shorten the sleeve to 100 rows and the same twelve rounds fall every eighth row, with four rows left over — worked plain at the top. Shorten it to ten rows and the shaping does not fit at all, which the calculator says rather than producing a frequency of less than one.
Where the answer misleads
An even taper is not how arms are shaped. A more tailored sleeve decreases faster through the upper arm and then runs nearly straight to the cuff, which follows the body more closely but needs two decrease rates rather than one.
Row gauge drives the whole calculation, and row gauge is the measurement knitters most often skip. Getting stitch gauge right and row gauge wrong produces a sleeve of the right circumference whose shaping finishes in the wrong place.
Finally, this assumes knitting in the round or a symmetrical flat sleeve. A sleeve with a set-in cap has its own shaping above the taper, and the two have to be planned together — the taper cannot use every available row.
Frequently asked questions
How often should I decrease on a sleeve?
Divide the sleeve length in rows by the number of decrease rounds. Going from 72 stitches to 48 over 120 rows is 24 stitches, so 12 decrease rounds, worked every tenth row.
Where do the decreases go?
At the underarm seam, one either side, paired so they mirror. On a seamless sleeve knitted in the round they sit either side of a single marked stitch, which becomes a faux seam line.
What if the numbers do not divide evenly?
Work the remainder as plain rows at the top of the sleeve, before the shaping starts, rather than at the cuff. Finishing the decreases a little early is invisible; running out of rows before the decreases are done is not.
Should the taper be even all the way down?
For most sleeves, yes. A more tailored sleeve decreases faster through the upper arm and then runs straight to the cuff, which follows the arm more closely but needs the decreases split into two rates.