Guides
Last updated: July 2026
Guides on markup, fees, break-even, and sales tax — each with worked numbers and a link to the matching calculator. Not tax or accounting advice. Not tax or accounting advice; see methodology for sources.
How to Calculate Markup (Without Confusing It With Margin)
Markup is profit ÷ cost. Worked example from a $20 cost, the 40% margin trap, a conversion table, and what belongs in unit cost.
Cost-Plus Pricing: When It’s Enough and When It Isn’t
Cost-plus is a fast first sticker. When marketplace fees and break-even mean you need more than a markup percentage — with a practical sequence.
Markup vs Margin: Same Profit, Different Percent
How to convert markup ↔ margin, who uses which word, and how to price from a target without mixing denominators.
Break-Even for a Shop: Units, Fixed Costs, and Contribution
Fixed ÷ (price − variable) with a worked monthly example, what to put in each bucket, and when blended SKUs need a sketch — not a fantasy.
Reverse Sales Tax: Pull Tax Out of a Total
Gross ÷ (1 + rate) with a worked $54 / 8% example, why multiplying the gross fails, and why we don’t look up your ZIP.
Etsy Fees: What You Actually Keep on a Sale
Listing, transaction, and processing on a worked $40 order — then recompute margin after fees. Defaults are editable; your dashboard wins.
Food Cost Percentage: Plate Cost vs Menu Price
Ingredients ÷ menu price, pricing from a target %, recipe cost pitfalls, and why labor doesn’t belong in food cost %.
FBA Profit Before You List: A Honest Sketch
Referral + fulfillment estimates against cost and price, what storage and ads leave out, and when Seller Central overrides the sketch.