How to Calculate Profit Margin (and How Markup Is Different)

There is a pricing mistake that quietly costs small businesses thousands of pounds and dollars every year, and it takes about thirty seconds to make. Picture this: you buy handmade candles for $12 each, you want “a 40% profit,” so you add 40% on top of your cost and list them at $16.80. Job done — except it isn’t a 40% profit at all. That’s a 40% markup, and your actual profit margin is only 28.6%. Learning how to calculate profit margin properly, rather than guessing at a markup and hoping for the best, is the difference between pricing that grows your business and pricing that slowly bleeds it dry.

The confusion is everywhere. Suppliers quote you in markup. Your accountant talks in margin. Online gurus use the two words interchangeably, as if 30% markup and 30% margin were the same thing. They never are. In this guide you’ll learn exactly how to calculate profit margin with a dead-simple formula, how markup differs, how to convert between the two in seconds, and how to price backwards from the margin you actually want. Grab a calculator — by the end, you’ll never mix them up again.

How to Calculate Profit Margin: The Formula

Profit margin is your profit expressed as a percentage of the selling price — the money the customer actually hands you. That’s the crucial detail most people miss: margin is always measured against revenue, not against what you paid.

Here’s the formula:

Profit Margin % = (Selling Price − Cost Price) ÷ Selling Price × 100

Let’s walk through it with friendly numbers. You sell a wallet for $100. It cost you $80 to source (that’s your cost of goods sold, or COGS — materials, manufacturing, shipping it to you, all in).

1. Find your profit: $100 − $80 = $20.
2. Divide by the selling price: $20 ÷ $100 = 0.20.
3. Multiply by 100: 0.20 × 100 = 20%.

Your profit margin is 20%. In plain English: of every $100 that comes through the till, you keep $20 after covering the cost of the goods.

Why the selling price and not the cost? Because margin answers the question every business owner actually cares about: “For each pound or dollar of sales I make, how much do I keep?” Investors, banks, and accountants all think in margin — gross margin and net margin on a profit-and-loss statement are the same idea, just with different costs subtracted. When someone says “healthy margins,” this is the number they mean.

What Markup Means (and Its Formula)

Markup is the same $20 of profit, but measured against a different yardstick: your cost price. It answers a different question — “How much did I add on top of what I paid?”

Markup % = (Selling Price − Cost Price) ÷ Cost Price × 100

Same wallet, same numbers:

1. Profit: $100 − $80 = $20 (unchanged).
2. Divide by the cost price: $20 ÷ $80 = 0.25.
3. Multiply by 100: 25%.

Your markup is 25%. Notice what just happened: the profit didn’t change by a single cent, yet the percentage jumped from 20% to 25%. That’s the whole trap. Markup will always give you the bigger, flattering number — which is exactly why suppliers and sales reps prefer quoting in markup, and why you should always translate it into margin before making decisions.

Profit Margin vs Markup: Side-by-Side Comparison

If formulas make your eyes glaze over, this table is the cheat sheet. Same sale, two perspectives:

One rule to tattoo on your brain: on any profitable sale, markup is ALWAYS the bigger number. If someone quotes you “50%,” ask which one they mean — because a 50% markup is only a 33.3% margin (you’ll see the maths in the conversion table below).

Worked Example 1 — From Cost and Price

Let’s do a realistic one. You make bars of handmade soap. Each bar costs you $4.50 all-in (oils, fragrance, packaging, the little paper band). You sell each bar for $9.

Step 1 — Profit per bar: $9.00 − $4.50 = $4.50.

Step 2 — Margin: $4.50 ÷ $9.00 = 0.50 → 50%.

Step 3 — Markup: $4.50 ÷ $4.50 = 1.00 → 100%.

So you can truthfully say “I make 50% margin” or “I mark up 100%” — and both describe the same $4.50. See how dramatic the gap gets? This is why comparing two businesses on “percentage profit” is meaningless unless you know which percentage each one is quoting.

Worked Example 2 — Pricing Backwards From a Target Margin

This is the move most pricing guides skip, and it’s the most useful one in real life. Instead of picking a price and hoping the margin works out, start from the margin you want and solve for the price.

Say an item costs you $60 and you’ve decided you need a 30% margin to cover your overheads and still make it worthwhile. What price do you charge?

The wrong way (and almost everyone does this first): add 30% to the cost. $60 × 1.30 = $78. But check the margin: profit is $18, and $18 ÷ $78 = 23.1%. You wanted 30% and got 23.1%. Ouch.

The right way — the backwards-pricing formula:

Selling Price = Cost Price ÷ (1 − Margin as a decimal)

Plug in the numbers: $60 ÷ (1 − 0.30) = $60 ÷ 0.70 = $85.71.

Let’s verify: profit = $85.71 − $60 = $25.71. Margin = $25.71 ÷ $85.71 = 0.30 → exactly 30%. That’s the price that actually delivers the margin you asked for. Memorise this formula — it’s the single most valuable equation on this page.

Worked Example 3 — Converting a Supplier’s Markup Into Your Margin

Your supplier emails: “New wholesale line — only a 40% markup on our $50 cost price!” Sounds steep, but what does it mean in margin terms, the language your own books speak?

Step 1 — The price you’d pay: $50 × 1.40 = $70.

Step 2 — The supplier’s profit: $70 − $50 = $20.

Step 3 — The supplier’s margin: $20 ÷ $70 = 0.2857 → 28.6%.

So their “40%” is really a 28.6% margin. Neither number is dishonest — they’re just different lenses. But now you see why fluency in both matters: when a supplier talks markup, translate it to margin before you decide whether the deal is actually good.

The Margin ↔ Markup Conversion Table

Sometimes you just need a quick lookup rather than the maths. This table shows the same

And if your number isn’t in the table, these two formulas convert either direction (use decimals, so 30% = 0.30):

• Margin from markup: Margin = Markup ÷ (1 + Markup). Example: 0.40 ÷ 1.40 = 0.286 → 28.6%.
• Markup from margin: Markup = Margin ÷ (1 − Margin). Example: 0.30 ÷ 0.70 = 0.429 → 42.9%.

Keep this table bookmarked — it ends more pricing arguments than any other reference I know.

How to Calculate Profit Margin in Excel and Google Sheets

If you’re pricing more than a handful of products, mastering how to calculate profit margin in a spreadsheet once means never doing it manually again. Put your cost price in cell A2 and your selling price in cell B2, then:

• Margin %: =(B2-A2)/B2 — then format the cell as a percentage.
• Markup %: =(B2-A2)/A2 — formatted as a percentage.
• Price needed for a target margin (target margin as a decimal in C2): =A2/(1-C2).
• Price with a given markup (markup as a decimal in D2): =A2*(1+D2).

Drag the formulas down your whole product list and you’ll see every margin and markup at a glance. Sort by margin, lowest first, and you’ve instantly found the products that are quietly underpriced — the ones to fix this week. (If you also wrestle with loan maths, our loan EMI calculation guide walks through that formula step by step.)

Where You’ll Actually Use This

This isn’t textbook theory. Here’s where the margin/markup distinction shows up in ordinary working life:

• Retail and e-commerce pricing. Every price tag you set is a margin decision, whether you did the maths or not. Doing it deliberately is what separates shops that survive from shops that don’t.
• Freelancers quoting projects. Your “cost” is your time valued at your target hourly rate plus expenses; your quote is the selling price. A 30% margin on a project quote is not the same as adding 30% to your costs — and clients negotiate against the quote, so margin is the number that protects you.
• Resellers judging supplier deals. Suppliers speak markup; your profit-and-loss speaks margin. Translate before you commit to stock.
• Restaurants and food businesses. Food-cost percentage is just the flip side of margin thinking — if your dish costs $3 in ingredients and sells for $12, that’s a 75% margin, and now you know exactly how much room a discount eats.
• Sanity-checking a “deal.” A supplier offering “cost plus 25%” sounds modest until you realise that’s a 20% margin on the sale — fine for high-volume goods, brutal for slow-moving stock.

5 Common Mistakes That Cost Real Money

1. Using a markup percentage where a margin was intended. The classic. You wanted a 30% margin, added 30% to cost, and actually earned 23.1%. Always check which base your percentage sits on.
2. Adding the margin percentage on top of cost. Margin is never “cost plus X%.” To hit a margin target, divide cost by (1 − margin) — Worked Example 2 above is the proof.
3. Assuming equal percentages mean equal money. “50% margin” and “50% markup” on the same cost produce wildly different prices ($120 vs $90 on a $60 cost). Never compare percentages across the two measures.
4. Thinking margin can reach 100%. It can’t — not while your cost is above zero. A 100% margin would mean keeping the entire selling price with zero cost, which means it wasn’t a sale, it was a gift you charged for. Markup, on the other hand, can exceed 100% easily (see the soap example: 100% markup, 50% margin).
5. Stacking markups down a supply chain. A 20% markup at the manufacturer, another 20% at the wholesaler, and 20% at retail does NOT equal 60% — it compounds to 72.8% (1.20 × 1.20 × 1.20 = 1.728). Convert each stage to margin if you want the true picture.

Frequently Asked Questions

You now know how to calculate profit margin and how markup differs. Margin versus markup isn’t academic hair-splitting — it’s the difference between the profit you think you’re making and the profit actually landing in your account. Learn the two formulas, keep the conversion table handy, and price backwards from the margin you want instead of forwards from the cost you paid. And when you’re ready to check your own numbers, run them through Calcnit’s free profit margin calculator to see your margin and markup side by side in seconds.