Two different measurements
The design size is the area the stitches cover: the stitch count divided by stitches per inch. The fabric size is what you cut, which must be bigger so there is room to hold the fabric in a hoop and to frame or finish the piece.
Working it out
- Design width = stitches across ÷ stitches per inch.
- Fabric width = design width + border on the left + border on the right.
- Repeat for the height.
A design 140 × 100 stitches on 14-count Aida is 10 inches wide and 100 ÷ 14 inches high. Adding 3 inches on every side gives a minimum width of 16 inches and a height of (100 ÷ 14) + 6 ≈ 13.143 inches. A 16 × 14 inch cut rounds the height upward and leaves at least the chosen border. Keep the unrounded calculation until you choose the cutting size.
How much border you need depends on how you will finish the piece. If someone else is framing it, ask what they need before you cut. See also fabric count.