Markup calculator
Price from cost, cost from price, or the markup hiding between them — with margin shown alongside, because they are not the same number.
A 50% markup on a $40 cost is a 33.3% margin — markup and margin describe the same $20 of profit against different bases.
The formulas
Markup % = (price − cost) ÷ cost × 100
Margin % = (price − cost) ÷ price × 100
Price = cost × (1 + markup ÷ 100) or cost ÷ (1 − margin ÷ 100)
One pool of profit, two denominators. Markup asks "how much did I add on top of what it cost me?" — margin asks "how much of the sale price do I keep?" Mixing them up always errs in the same painful direction: pricing for a "40% margin" by multiplying cost by 1.4 actually delivers a 28.6% margin. If you want margin, divide by (1 − margin); never multiply.
Markup ↔ margin conversion chart
| Markup | Margin |
|---|---|
| 10% | 9.1% |
| 15% | 13.0% |
| 20% | 16.7% |
| 25% | 20.0% |
| 30% | 23.1% |
| 40% | 28.6% |
| 50% | 33.3% |
| 75% | 42.9% |
| 100% | 50.0% |
| 200% | 66.7% |
The famous row is 100 ↔ 50: doubling your cost — keystone pricing — keeps half of every sale. Notice how the gap widens as numbers grow; at small markups the two are nearly interchangeable, which is exactly why the confusion survives.
A worked example
A candle maker's true cost per unit is $11.20 — wax, wick, jar, label, and the 34 minutes of labor most spreadsheets forget. At a 120% markup she wholesales for $24.64 (a 54.5% margin, $13.44 profit). The boutique she sells to applies keystone and retails at $49.28. Every party priced with markup; every party's accountant will read it back as margin.
The number that quietly goes stale
A markup is only as honest as the cost under it — and cost moves. Your supplier reprices resin, freight jumps, and the "50% markup" you set in January is a 34% markup by June without a single price change on your side. That drift is invisible in a spreadsheet because the cost cell never updates itself. Ininventory software the cost basis re-averages with every receipt, so the margin column on every item is live — the moment a supplier price erodes it, you see it, item by item, before the quarter does.