What This Calculator Does
The Knitting Yarn Yardage Calculator estimates how much yarn — and how many full skeins — you need to complete a knitting project. By combining your project's dimensions with how densely your stitch pattern and gauge consume yarn (yards per square inch), it gives you a practical shopping number so you don't run short mid-project or overbuy.
How to Use It
Enter the finished width and height of your project in inches. Then provide your yards per square inch — a value you can calculate by knitting a gauge swatch, measuring its area, and dividing the yardage used by that area. Finally, enter the yards per skein printed on your yarn's label. The calculator multiplies width by height to get area, scales that by yards per square inch for total yardage, and divides by skein length, rounding up because you can only buy whole skeins.
The Formula Explained
The math is straightforward: total_yards = (width × height) × yards_per_sqin and skeins = ceil(total_yards / yards_per_skein).
$$\text{Skeins} = \left\lceil \frac{\text{Width} \times \text{Height} \times \text{Yards/in}^2}{\text{Yards/Skein}} \right\rceil$$
The ceiling function guarantees you have enough yarn even if the division leaves a remainder. Adding 5–10% to your yards-per-square-inch value is wise to cover seams, edging, and dye-lot insurance.
Worked Example
Suppose you're knitting a 40 in × 60 in blanket. Your swatch tells you the pattern uses 0.25 yards per square inch, and each skein holds 220 yards. Area = \(40 \times 60 = 2{,}400\) sq in. Total yards = \(2{,}400 \times 0.25 = 600\) yards. Skeins = \(\lceil 600 / 220 \rceil = \lceil 2.73 \rceil = 3\) skeins.
FAQ
How do I find yards per square inch? Knit a swatch, note how many yards it took, measure its area in square inches, and divide yards by area.
Should I buy extra? Yes — buying one extra skein of the same dye lot protects against running out and color mismatches.
Does this work for crochet? Yes, the same area-based method applies; just measure yards per square inch from a crochet swatch.
