Sales and Profit Calculator: How to Use It

This calculator works out your profit (or loss) from a sale: enter the cost price, the selling price, and the quantity sold, and it returns the total profit, the profit per unit, and the profit margin percentage. It also shows the markup percentage if you want to compare pricing strategies. Use it for any product or service where you know what you paid and what you charged.

Formula

The core formulas are straightforward:

• Profit per unit = Selling price − Cost price
• Total profit = Profit per unit × Quantity sold
• Profit margin = (Profit per unit ÷ Selling price) × 100
• Markup = (Profit per unit ÷ Cost price) × 100

Where:

• Cost price – what you paid to acquire or make one unit (in dollars, euros, etc.)
• Selling price – what the customer pays for one unit
• Quantity – number of units sold
• Profit margin – profit as a percentage of the selling price
• Markup – profit as a percentage of the cost price

Worked Example

Using the default values: cost = $10, selling price = $15, quantity = 100.

1. Profit per unit = $15 − $10 = $5
2. Total profit = $5 × 100 = $500
3. Profit margin = ($5 ÷ $15) × 100 = 33.3%
4. Markup = ($5 ÷ $10) × 100 = 50%

The calculator returns: total profit $500.00, margin 33.3%, markup 50.0%.

Why Margin and Markup Are Different

Many people use “margin” and “markup” interchangeably, but they are not the same. Margin is profit relative to the selling price; markup is profit relative to the cost. A 50% markup does not mean a 50% margin – as shown above, a 50% markup gives a 33.3% margin. This distinction matters when you set prices or negotiate discounts. If you aim for a 40% margin, you cannot just add 40% to your cost; you need to divide the cost by (1 − 0.40). For example, a $10 cost with a 40% margin means selling price = $10 ÷ 0.60 = $16.67.

Common Mistakes and How to Avoid Them

• Mixing up cost and selling price in the denominator – margin uses selling price, markup uses cost. Check which one you need.
• Forgetting to include all costs – the cost price should include shipping, packaging, transaction fees, and any other per-unit expense, not just the wholesale price.
• Using the wrong quantity – if you sell 100 units but 5 were returned, your profit is based on 95 net sales.
• Rounding too early – round only the final result, not intermediate steps, to avoid small errors that compound.
• Ignoring fixed costs – this calculator gives gross profit (per unit minus cost). Rent, salaries, and utilities are not included; net profit requires subtracting those separately.

How to Choose the Right Numbers

For a product you buy wholesale, the cost is what you pay the supplier. For a service, the cost might be your hourly labor plus materials. For a digital product, the cost could be near zero, but you might include payment processing fees. The selling price is what the customer actually pays, before any discounts or taxes. If you run a promotion, use the discounted price as the selling price to see the true profit. For subscription or multi-unit bundles, enter the per-unit price and total quantity.

Limits of This Calculator

This calculator assumes a simple linear relationship: profit = (price − cost) × quantity. It does not account for:

• Variable costs that change with volume (e.g., bulk discounts from suppliers)
• Fixed costs (rent, equipment, salaries) that don’t scale per unit
• Taxes, which vary by jurisdiction and product type
• Discounts, refunds, or chargebacks
• Currency conversion if you buy and sell in different currencies

For a full business picture, combine this with a break-even analysis that includes fixed costs.

Frequently Asked Questions

What is the difference between profit margin and markup?

Profit margin is profit as a percentage of the selling price. Markup is profit as a percentage of the cost price. For example, if you buy for $10 and sell for $15, your markup is 50% (profit $5 divided by cost $10), but your margin is 33.3% (profit $5 divided by selling price $15).

How do I calculate the selling price to get a desired margin?

Divide the cost by (1 − desired margin as a decimal). For a 40% margin on a $10 cost: $10 ÷ (1 − 0.40) = $16.67. That gives you the selling price that yields a 40% margin.

Does this calculator include taxes?

No. Taxes are not included in the cost or selling price. Sales tax is collected from the customer and remitted to the government, so it does not affect your profit. Income tax on profits is separate and depends on your total business income.

Can I use this for services instead of products?

Yes. For a service, enter your cost per hour (including your time and materials) as the cost, and the hourly rate you charge as the selling price. Quantity would be the number of billable hours. For fixed-price projects, treat the project as one unit.

What if I sell multiple products with different costs?

Calculate each product separately, then sum the profits. Alternatively, use a weighted average cost and price, but that can hide which products are more profitable. It is usually better to analyze per product.

Why does the margin percentage not match my expected profit?

Check that you are using the correct formula. Margin = profit ÷ selling price × 100. If you are dividing by cost, you are calculating markup. Also ensure your cost includes all per-unit expenses, not just the purchase price.

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in cost | Cost per unit | $ | 10 | 0
in price | Selling price per unit | $ | 15 | 0
in qty | Quantity sold | units | 100 | 1
out profit | Total profit | $ | (price - cost) * qty | 2
out margin | Profit margin | % | (price - cost) / price * 100 | 1
out markup | Markup | % | (price - cost) / cost * 100 | 1