Business calculator
Five business calculators in one tool: ROI, margin, discount price, break-even units and Korean 10% VAT, each with a visible formula.
Formula estimate only. Rates, taxes, and legal rules vary by jurisdiction.
What to know
The business calculator switches between five modes, and each mode reveals only the fields it needs. ROI and margin ask for a cost and a sale value, discount asks for a price and a rate, break-even asks for price, variable cost and fixed cost, and the Korea VAT mode takes a won amount.
The formulas are ROI = (final - cost) / cost x 100, margin = (revenue - cost) / revenue x 100, discounted price = price x (1 - rate), and break-even units = fixed cost / (price - variable cost), rounded up. The VAT mode divides by 1.1 or multiplies by 0.1 in whole won.
The most common confusion is margin versus markup. Margin divides profit by the selling price, while markup divides profit by cost, so 700 cost and 1,000 price is a 30 percent margin but a 42.86 percent markup. Only the margin is calculated here.
Each mode shows a short summary, such as net change for ROI or contribution per unit for break-even, and a copy button on every line. Costs and revenues can be entered in USD, KRW, JPY, CNY or EUR, and no tax, fee or inflation adjustment is applied.
Choose a specific task 5
Related tools 3
How to use Business calculator
- Open the mode that fits the question, such as margin.
- Enter Cost 700,000 and Sale or final value 1,000,000.
- Check that the Margin rate line shows 30%.
- Open the break-even mode to size the sales target against fixed costs.
Quick answers
Which mode do I use to price a product with a target margin?
Margin tells you the rate for a given cost and price. For a target, rearrange it: price = cost / (1 - margin), so 700 cost at 30 percent margin needs 1,000.
Does break-even include taxes or financing costs?
No. It uses only the fixed cost, price and variable cost you enter, and it rounds the unit count up to the next whole unit.
Can ROI be negative?
Yes. When the final value is below the cost the percentage turns negative, for example 800,000 from 1,000,000 gives -20%.