Temperature Blanket Yarn Calculator
Yarn for a temperature blanket is not one number, because every color covers a different number of days. Enter your gauge and width and get yards and skeins for each color.
1. City and year
285 US cities. Each one uses the nearest NOAA weather station that reports every day.
2. Temperature ranges and colors
Each band includes its lower number and stops just below its upper number. Free: up to 8 bands.
3. Style
4. Craft and gauge
Yards per stitch depends on yarn weight and stitch. The defaults are typical for worsted yarn; measure a swatch and edit them.
Pick a city to see its year
Your blanket appears here as soon as the weather loads: one colored row for every day, with the number of days and yards for each color.
Colors, days and yarn
| Color | Range °F | Days | Rows | Yards | Skeins | Match to your yarn |
|---|
Daily table: date, temperature, color
| Date | High °F | Color | Data |
|---|
The math
For a blanket worked in rows, the yarn for one color is: the days in that color, times rows per day, times stitches per row, times yards per stitch, plus a margin for ends. Stitches per row come from the blanket width and your stitches-per-inch gauge.
With the defaults (50 inches wide, 3.5 stitches per inch, one row a day) a row has 175 stitches. At about 0.065 yard per single crochet stitch in worsted yarn and 10% extra for ends, a full year of 365 rows comes to roughly 4,567 yards across all colors. A color with 40 days needs about 501 yards.
Measure your own yards per stitch
The one number that varies most between makers is how much yarn a stitch uses. It depends on the stitch, the hook or needle and your tension. To measure it, work a swatch of known stitches, for instance 20 stitches by 10 rows, and weigh it or measure the yarn you used. Divide yards used by 200 stitches. Type that figure into “Yards per stitch” and the whole table follows it.
Knit stockinette in worsted weight uses less per stitch than crochet, which is why the knit defaults are lower: about 0.032 yard per stitch against 0.065 for single crochet.
Skeins and dye lots
Skeins are rounded up for each color, using the yards per skein you enter (200 is common for a worsted skein; check your label). If a color is just under a skein boundary, buy one more: it is cheaper than finding the same dye lot in March. Keep the leftover for the next year’s blanket border.
The counts and yarn estimate are free. The free planner covers any city and year, up to 8 color bands, the preview, counts and a daily table. The Planner Pack ($3.99, one-time) adds the printable chart, checklist and yarn list. See pricing.
The Planner Pack adds the yarn shopping list as a print-ready page, so you can take the list to the shop.
Questions
How much yarn does a temperature blanket take?
It depends on width, gauge, rows per day and stitch. For a 50-inch single crochet blanket with one row a day in worsted yarn, expect roughly 4,500 yards. Enter your own numbers above for a figure that fits your blanket.
How many rows per day?
Most people do one row per day. Two rows per day makes a bigger, warmer blanket and doubles the yarn, and some people use one row for the high and one for the low. Change “Rows per day” and the length and yarn update.
Are the yarn numbers exact?
No. They are estimates from your gauge and a typical amount of yarn per stitch, plus ten percent for ends. Work a swatch and edit the yards per stitch for a closer figure.
How many colors should I use?
Eight to ten is common: each color covers about 5 to 10 degrees Fahrenheit. Fewer colors make bold, long stripes. More colors show small changes but need more yarn colors to buy and more ends to weave in.