Margin vs. markup (profit basis)

Margin is profit as a percent of the selling price (the retail and accounting convention). Markup is profit as a percent of your cost. At 10% on a $1,000 item: margin demands $1,111.11 (profit is 10% of what the buyer pays); markup demands $1,100 (profit is 10% of what you paid). The gap grows with the percentage.

Choose your basis under Settings → Defaults. Every target, ladder, and realized percentage in the app follows it. Note that switching reinterprets your stored target numbers rather than converting them — "10" means 10% margin under one basis and 10% markup under the other, which are different prices.