Throw Adult-Blanket: Size, Gauge and Yarn Amount
A throw is the smallest of this site's four adult blanket sizes and the most common size for a sofa or armchair piece — big enough to actually cover someone sitting under it, small enough to still finish in a realistic timeframe rather than becoming a months-long project.
Dimensions
This page works from 50 by 60 inches — a standard throw dimension that drapes comfortably over a couch back or across a lap on an armchair, without the bulk of a bed-scale blanket.
Cast-on
225 is what 50 inches times 4.5 stitches per inch works out to — one over a clean multiple of 4, so 224 stitches is the actual foundation chain length. The same math applies whether you're casting on for knit or starting a crochet foundation chain; the Cast-On Calculator takes your own measured gauge instead of this page's example figure.
Yarn amount, and a gauge note worth reading first
At a double crochet gauge of 4.5 stitches, 6 rows per inch, the Yarn Quantity Estimator puts this piece at 4,755 yards (4,323 base yards plus a 10% allowance). That gauge is deliberately kept consistent with this site's other blanket-size worked examples, but it's noticeably finer than a typical double crochet gauge — real double crochet worked at a relaxed, typical tension commonly runs closer to 2.5-3 stitches per inch, not 4.5. Treat the figure above as this page's specific, reproducible worked example, not a general "double crochet blanket" rule of thumb, and re-run your own actual measured gauge through the calculator before buying yarn. This site's other three adult blanket sizes use the identical reference gauge for the same reason — direct comparability across sizes — rather than as a gauge recommendation.
Why crochet yarn-use estimates deserve extra caution here
This site's own methodology is explicit that double crochet's yarn-use constant carries more uncertainty than knit stitch patterns do — published lab studies and this site's direct-project calibration disagree on the actual direction of crochet-versus-knit yarn use at matched gauge, and the site states that disagreement rather than picking a side. At blanket scale, where the total yardage involved is large enough that a wrong estimate is expensive to discover late, weighing an actual swatch (the calculator's swatch-weighing mode) is worth the extra few minutes over trusting a gauge-model figure alone.
A throw's realistic timeline
Even at this site's smallest adult blanket size, several thousand yards of double crochet is a real time commitment — plan for a project measured in weeks or months of regular work rather than a quick weekend piece, and consider a modular, motif-based construction (see the granny square motif) if working one large continuous piece for this long feels daunting.
Other adult blanket sizes
Twin, Full-Queen, and King scale this same worked example up.
FAQ
Why does this page use a knit-like tight gauge for a crochet blanket instead of a typical looser dc gauge? It's a deliberate worked-example choice to keep the four adult blanket sizes on this site directly comparable to each other and to the baby blanket sizes, which share the same reference gauge — it's explicitly not a claim that this is a typical or recommended double crochet gauge, and the page says so above.
Would working this throw in single crochet instead of double crochet change the yarn total meaningfully? Yes, and not necessarily in the direction you'd expect — this site's own calibration finds single crochet's yarn-use constant is actually somewhat higher than double crochet's per stitch at matched gauge, which runs against the common assumption that a taller stitch always uses more yarn; see the methodology page for the full explanation.
Is a throw a reasonable first blanket project, or does that come with the same scale challenges as a bigger blanket? It's the most manageable of this site's four adult blanket sizes for a first attempt — still substantial, but noticeably less unwieldy in your lap during the many hours of work than a twin- or queen-scale piece would be.