Calculate perfectly spaced decreases for your knitting project
Your Instructions:
How to Use the Knitting Decrease Calculator
When a knitting pattern says "Decrease 8 stitches evenly across the row," it can be frustrating to figure out the math on the fly. This calculator does the heavy lifting for you, ensuring your decreases (like K2tog or SSK) are spaced perfectly for a professional look.
The Math Behind Decreasing Evenly
To decrease stitches evenly, you need to divide your current stitch count by the number of decreases required. However, because you can't knit "half a stitch," we often have to alternate between two different spacing sequences to get the math exactly right.
Common Knitting Abbreviations
K: Knit
K2tog: Knit two stitches together (right-leaning decrease)
SSK: Slip, slip, knit (left-leaning decrease)
Sts: Stitches
Practical Example
Imagine you have 50 stitches on your needle and you need to decrease 6 stitches.
If you knit 6 and then K2tog (which uses 8 stitches total) 6 times, you would use 48 stitches, leaving 2 stitches at the end of the row. Our calculator would distribute those remaining stitches so the pattern looks balanced.
Tips for Perfect Shaping
1. Symmetry: If you are knitting a sleeve or a neckline, ensure you use the same decrease type (like K2tog) consistently across the row.
2. Row Type: Decreases are typically worked on the "Right Side" (RS) rows unless the pattern specifies otherwise.
3. Check Your Work: Always count your stitches after a decrease row to ensure you have reached your target number before proceeding.
function calculateKnittingDecrease() {
var total = parseInt(document.getElementById('totalStitches').value);
var dec = parseInt(document.getElementById('decreasesNeeded').value);
var resultDiv = document.getElementById('knittingResult');
var instructionBox = document.getElementById('instructionText');
var summaryBox = document.getElementById('summaryText');
if (isNaN(total) || isNaN(dec) || total <= 0 || dec total) {
alert('You cannot decrease that many stitches. Each decrease (like K2tog) requires at least 2 stitches.');
return;
}
// Logic: Each 'decrease block' consists of K(n) and a K2tog.
// A K2tog uses 2 stitches.
// Let's find the base interval
var stitchesPerDec = Math.floor(total / dec);
var remainder = total % dec;
// In knitting "Decrease 10 over 80", 80/10 = 8.
// This means every 8 stitches, a decrease occurs.
// Instruction: (K6, K2tog) x 10 times.
var patternA_totalSts = stitchesPerDec;
var patternB_totalSts = stitchesPerDec + 1;
var countB = remainder;
var countA = dec – remainder;
var kA = patternA_totalSts – 2;
var kB = patternB_totalSts – 2;
var instruction = "";
if (remainder === 0) {
instruction = "Repeat (K" + kA + ", K2tog) " + dec + " times.";
} else {
instruction = "Work (K" + kB + ", K2tog) " + countB + " times, then (K" + kA + ", K2tog) " + countA + " times.";
}
var targetStitches = total – dec;
resultDiv.style.display = 'block';
resultDiv.style.backgroundColor = '#f4f1f6';
instructionBox.innerHTML = instruction;
summaryBox.innerHTML = "Summary: Starting with " + total + " sts, you will decrease " + dec + " sts to end with " + targetStitches + " sts.";
}