Percentage calculator
What is X% of Y, X is what percent of Y, and percentage increase or decrease — the three questions behind most 'quick maths' searches.
result = value × percent ÷ 100
Home/Business Calculators
// Free tools
Eight business calculators, no signup, no tracking
Percentage, discount, margin and markup, break-even, ROI and ROAS, customer lifetime value, loan instalment and compound interest — the calculations that come up most often in running a shop. Everything runs in your browser; nothing is sent anywhere.
Discount & sale price
Take a list price and a discount and get the sale price, the money saved and the effective margin hit. The number every promotion decision starts from.
sale = list × (1 − discount ÷ 100)
Profit margin & markup
The two numbers that get confused most often, and the confusion is expensive. A 50% markup is a 33% margin — price on markup when you meant margin and you have quietly given away a third of your profit.
margin % = (price − cost) ÷ price × 100 · markup % = (price − cost) ÷ cost × 100
Break-even point
How many units you must sell before you stop losing money. Fixed costs divided by the contribution each unit makes — the sanity check before any product launch.
units = fixed costs ÷ (price − variable cost)
ROI & ROAS
Return on investment and return on ad spend. ROAS tells you whether a campaign made revenue; ROI tells you whether it made money. They are not the same, and only one pays salaries.
ROI % = (gain − cost) ÷ cost × 100 · ROAS = revenue ÷ ad spend
Customer lifetime value
What a customer is worth over the whole relationship. In B2B this is the number that justifies your acquisition cost — and it is almost always higher than people assume.
CLV = order value × orders per year × years × margin %
Loan / instalment (EMI)
The monthly payment on a loan or a financed investment, plus what it costs you in interest over the term. Useful before signing for that new warehouse system.
EMI = P × r × (1+r)ⁿ ÷ ((1+r)ⁿ − 1)
Compound interest
What an amount grows to when the return compounds. The same maths behind savings, inflation and why a 2% monthly growth rate is a very different number after a year than people expect.
A = P × (1 + r ÷ n)^(n × t)
// The one that costs money
Margin is not markup — and the difference is a third of your profit
If a product costs you 60 and you want to "make 50%", which 50% do you mean? Add 50% to the cost and you sell at 90 — that is a 33% margin, not 50%. To actually make a 50% margin you must sell at 120. Every year we find shops that have priced an entire catalogue on the wrong one.
| Cost | Markup | Selling price | Actual margin |
|---|---|---|---|
| 60 | 25% | 75 | 20% |
| 60 | 50% | 90 | 33% |
| 60 | 100% | 120 | 50% |
| 60 | 150% | 150 | 60% |
// FAQ
About these calculators
Margin is profit as a percentage of the selling price; markup is profit as a percentage of the cost price. A 50% markup on a 60 cost gives a 90 price — which is only a 33% margin. Confusing the two is one of the most common and most expensive pricing mistakes in e-commerce.
It depends entirely on your margin. At a 20% gross margin, a ROAS of 4 loses money: €4 of revenue carries only €0.80 of gross profit against €1 of ad spend. That is why this calculator asks for your margin and shows the real ROI as well as the ROAS.
No. Everything runs in your browser. Nothing is sent to a server, nothing is stored, and there is no tracking on the results — you can check that in the page source.
Yes — product configurators, price and quantity calculators, financing calculators and ROI tools are a regular part of our work. In a B2B shop, a calculator that answers the buyer's real question is often a stronger conversion lever than any redesign.
Divide the cost by one minus the margin — do not add the margin to the cost. For a 40% margin on a cost of 60: 60 ÷ 0.6 = 100. Adding 40% instead gives 84, which is a 29% margin and a quiet loss on every single unit. The margin calculator above shows both numbers at once, so you can see which one you actually meant.
Measure it against your margin, not against the price. At a 30% margin, a 15% discount does not cost you 15% — it halves your profit, because the whole discount comes out of the margin. At a 30% margin, a 30% discount leaves you exactly nothing. Put your list price into the discount calculator above and read the margin line, not the saving.
Only if you put it in. Fixed costs means everything that happens whether or not you sell a single unit: rent, salaries — including your own — software, insurance. Most people leave their own time out and then wonder why a product that looks profitable never funds anything. Variable costs are only what one additional unit genuinely costs you.
Need a calculator inside your shop?
Configurators, price and financing calculators, ROI tools — built into Shopware or as a standalone app.