When I went looking for a link to include in an AntiCraft article about how to measure and cut canvas for counted needlepoint, I found exactly two. They were both by the same person, and they were both Wrong. (Seriously, I'm still spluttering over just
how wrong!) None of the sites devoted to needlepoint and cross stitch seem to realize that before you can get to "step 1: bind the edge of the canvas to prevent fraying," you have to figure out where that edge should be.
So, I'll tell you. Isn't that kind of me? ;)
There are many different kinds of canvas that can be used for needlepoint. You can even use plain woven fabric if you're a
masochist expert. But, if you're new enough to stitchery that you don't already know how to measure your canvas for your project, you'll most likely be using aida cloth, so that's what I'll talk about here.
Aida cloth comes in many different "counts" or "points," which refers to the size of the weave. A point is the space for one stitch in basic
continental or
cross stitch; it's where the vertical threads and the horizontal threads intersect. The number of points refers to the number of stitches you can make over one inch. 11 count aida will have 11 stitches in one inch. 16 count will have 16 stitches in an inch, and so on. It's possible the canvas may be a point off here or there, but unless you're planning to stitch a wall-sized tapestry, it probably won't be enough of a difference to matter.
If you have purchased your pattern from a regular pattern company it may tell you how many stitches high and wide the design is. If you can't find this information you'll have to count the stitches yourself. If the design is not a regular shape, be careful to count from the very lowest stitch to the very highest, and from the left-most to the right-most. Write these numbers down.
Now, divide each of these numbers by the count of your fabric. For example, lets say that our pattern is 200 stitches high by 150 stitches wide.
On 11 count aida:
200/11 = approx. 18 inches high
150/11 = approx. 14 inches wide
On 18 count aida:
200/18 = approx. 11 inches high
150/18 = approx. 8.5 inches wide
On 22 count aida:
200/22 = approx. 9 inches high
150/22 = approx. 7 inches wide
You can see that the higher the count of the canvas, the smaller the pattern will be when it's finished.
So, that's how you figure the size of your stitched area, but it's
not the size you want to cut your canvas. Once you have your stitched size, you want to add a minimum of 3 inches to each side (adding 6 inches total to each dimension), possibly more, depending on the size of the stitching frame or hoop you'll be using. Using our 200 by 150 stitch example:
On 11 count aids:
18" + 6" = 24" high
14" + 6" = 20" wide
On 18 count aida:
11" + 6" = 17" high
8.5" + 6" = 14.5" wide
On 22 count aida:
9" + 6" = 15" high
7" + 6" = 13" wide
That's the size, at minimum, you cut your canvas. Any less and you'll risk not having enough room at the edges to mount the canvas in a frame or hoop to work the design completely, or to mount or sew the finished design into the display frame or other project for which you've stitched it.
Now you can proceed to "step 1: bind the edge of the canvas to prevent fraying."
Let me know if you need help with that, too. ;)
Flask Jacket: A sewn fabric cover for a hip flask. "Dress up a plain hip flask for a night at the cemetery, cover the claw marks left on it from the last full moon, or just remind yourself which flask has the whiskey and which has the O-negative."
Restraint: "It's what you apply to your slave's wrist or ankle. 
Hoist By Your Own Picard: A cordial. "Tea. Earl Grey. Hard."
Terpon's Cup: A spiced honeydew melon cordial. "I'd like to think Terpon might have made libation of such a drink as this in honor of noble Aphrodite."
Review: Xela's Disposable Flasks. Perfect for sharing your home made, um...infusions with distant friends.
