How the three modes work
Cost + price is the audit mode: it tells you the margin you are actually earning. Cost + margin is the pricing mode: enter the margin you need and it returns the selling price — computed as cost ÷ (1 − margin), not cost × (1 + margin), which is the mistake that quietly under-prices products. Price + margin works backwards to the maximum you can afford to pay a supplier.
What counts as "cost"
Gross margin should carry every direct cost of the sale: the item, inbound freight, payment processing if you attribute it per-order, packaging. Rent and salaries stay out — those belong to operating margin, one level down the P&L. Consistency matters more than the exact rule: use the same definition across products or the comparison is meaningless.
Typical gross margins
Grocery runs 15–25%, general retail 30–50%, restaurants ~60–70% on food (before labor eats it), software 70–90%. If your margin looks wildly off these bands, check whether you priced with markup arithmetic by accident — divide, don't multiply.