Markup Calculator

How to use it

Three fields decide everything:

• Cost — the full cost basis: purchase price plus cleaning, repair, shipping to you and packaging. Not just the sticker you paid.
• Selling price — what the item actually goes for, or your planned ask.
• Target margin — the share of the price you want to keep. The calculator answers with the price that margin requires.

The form opens on example numbers: cost 25, price 60, target margin 40%. Read the first two results as a pair — 140% markup, 58.3% margin — and the third as a route in reverse: a 40% margin on a 25 cost needs a price of 41.70.

Markup vs margin: the formula difference

Two conversions do the reverse trip — from a percentage back to a price:

The two scales never match: margin is always the smaller number, because the price is bigger than the cost. At a 100% markup the profit equals the cost, so the profit is exactly half the price — 100% markup, 50% margin. The glossary pages ROI vs margin vs markup and gross vs net margin place both numbers among their neighbours.

Worked example: one flip, markup and margin side by side

Say you buy trainers for 20 and spend 5 on cleaning and new laces. Cost basis: 25. You sell them at 60.

• Profit: 60 − 25 = 35
• Markup: 35 ÷ 25 = 140%
• Margin: 35 ÷ 60 = 58.3%

Same 35, two stories. The markup tells you what each unit of buying money earned — useful when you're deciding whether the sourcing trip paid. The margin tells you what share of the sale you kept — useful when you're setting prices or comparing categories with different price levels. For return on money against time, the reselling ROI calculator adds the days the cash was tied up.

How marketplace fees change the markup you need

Fees come off the price, so they hit the margin first. Allegro Lokalnie's fee page, checked 13 September 2026, charges 7.9% of item value for Kup teraz listings (4.9% in Elektronika). On the trainers: 7.9% of 60 is 4.74, profit falls to 30.26, and the margin drops from 58.3% to 50.4% — the fee took almost exactly its own 7.9 points. That is the general rule: at a fixed price, a percentage fee lowers your margin point for point.

Markup absorbs the hit unevenly — hard when cost sits close to price, lightly when the flip was cheap. To price for a margin after fees, the conversion gains a term:

The trainers at a 40% target margin and the 7.9% fee: 25 ÷ (1 − 0.079 − 0.40) = 48. Skip the fee term and the formula says 41.70 — a price at which the fee pushes your real margin below target. For your own marketplace's numbers, the marketplace fee calculator turns a fee rate and a price into the payout you'd actually receive; if your platform isn't in the presets, say the marketplace takes 10% and type 10 into the fee field — the arithmetic doesn't change.

Common mistakes: marking up on the wrong base

• Quoting a percentage without naming its base. 35 profit on a 25 cost is 140% markup or a 58.3% margin. "About 50%" describes neither, and pricing for "a 50% markup" (37.50) against "a 50% margin" (50) is a 12.50 difference per item.
• A cost basis with holes. Leaving out the 5 of laces and cleaning turns a 140% markup into a fictional 200%. If the money left your pocket for that flip, it belongs in cost.
• Converting margin to price without the fee. Cost ÷ (1 − margin) assumes the marketplace takes nothing. With a 7.9% fee and a 40% target, the honest divisor is 0.521, not 0.6.
• Aiming at 100% margin. The divisor (1 − margin) reaches zero — there is no finite price with a 100% margin. Margins above roughly 70% on resold goods deserve a re-check of the cost basis before celebration.
• Letting the markup set the price. The markup you need and the price the market pays are separate questions. Comparables cap the price; if the cap sits below your floor, the deal fails at the buy, not at the listing.

Where cost-plus helps and where it misleads

Cost-plus earns its keep twice: as a floor, the number below which a sale loses money once fees are counted, and as a buying filter — the same formula run backwards tells you the most you can pay at a flea market and still hit your margin. That is quick mental arithmetic you can do while holding the item.

It misleads as a ceiling. A 140% markup on an item nobody wants is still a bad buy, and no target margin creates demand. Price levels come from the market; the cost-plus number only tells you whether the market's price is worth your money.

For the wider money picture — profit with every cost in its place, cash tied up in stock, margins by month — the resale profit guide collects the tools, and the resale profit calculator runs a full flip with fees and shipping.

Related guides

• gross margin vs net margin
• what a good resale margin means
• estimating risk before you buy