Choose a count the pattern can use
Target stitches = target width × measured stitches ÷ measured span. A valid body count is n × repeat + offset, with at least one complete repeat. The calculator shows the valid counts on either side and their estimated widths.
At 18 stitches per 10 cm, a 100 cm target gives 180 stitches. For a body rule of 6n + 2, choose 176 stitches (about 97.8 cm) or 182 (about 101.1 cm). If the target is already valid, both options match.
Read the pattern for foundation chains, turning chains and edge treatment. The tool doesn't translate a foundation-chain multiple into body stitches. Width estimates assume your measured gauge continues across the body.