Price / Quantity Calculator
Enter any two of price per unit, total cost, and quantity to instantly solve for the third. Switch to Compare mode to find which product offers the best unit price, or use Profit mode to calculate gross profit and margin from cost and selling price. Results update as you type.
Formula
Worked example
A box of 10 pens costs $30: price per unit = $30 / 10 = $3.00. If you then sell each pen for $5, profit per unit = $5 - $3 = $2, total profit on 25 pens = $2 × 25 = $50, margin = $50 / $125 = 40%.
What is a price per unit calculation?
The price per unit tells you how much one item costs when you buy a pack or bundle. The formula is straightforward: price per unit = total cost / quantity. For example, a 12-pack of water bottles priced at $4.80 works out to $0.40 per bottle. This single figure lets you compare products of different pack sizes on an equal footing, which is why it appears on supermarket shelf labels and unit price apps alike. The reverse calculation - total cost = price per unit × quantity - is just as useful when you know the rate and want to budget for a specific number of units.
How the five modes work
This calculator covers five common pricing tasks. "Find price per unit" divides a total cost by a quantity to give you the unit rate. "Find total cost" multiplies a unit price by a quantity - useful when ordering a known number of items. "Find quantity" divides a budget by a unit price to tell you the maximum you can afford. "Compare two products" calculates the unit price for each and shows which is cheaper per unit and by how much - the bulk-buy decision tool. "Profit and margin" takes a cost price and a selling price and returns gross profit per unit, total profit, profit margin (profit / revenue), and markup (profit / cost), together with a revenue-cost-profit chart across a range of quantities.
Margin vs. markup: what is the difference?
Profit margin and markup both describe how much profit you make, but they use different denominators. Margin divides profit by revenue: if you sell an item for $10 that cost you $6, the profit is $4 and the margin is 4/10 = 40%. Markup divides profit by cost: the same $4 profit on a $6 cost is 4/6 ≈ 66.7% markup. Confusing the two is a common pricing mistake. If you set prices by saying "I want a 50% markup," that is very different from "I want a 50% margin." A 50% markup on a $6 item gives a $9 selling price (margin 33%), whereas a 50% margin on a $6 item gives a $12 selling price (markup 100%).
Choosing the best bulk pack
Supermarkets and wholesalers often present the same product in several pack sizes at different headline prices. Use the "Compare two products" mode to cut through this: enter the price and quantity of each option and the calculator shows you the unit price for both. The cheaper unit price is the better deal, assuming quality and shelf life are equal. Be aware that a bulk pack only saves money if you use all of it before it expires, and that unit price ignores storage cost, waste, and cash tied up in stock.
Profit margin benchmarks by industry
| Industry | Typical gross margin | Signal |
|---|---|---|
| Grocery / food retail | 2-5% | Thin - volume-driven |
| Restaurant / cafe | 60-70% | High gross, low net after costs |
| Software / SaaS | 70-90% | Very high - low cost of goods |
| Manufacturing | 20-40% | Moderate |
| Retail (general) | 30-50% | Moderate |
| E-commerce | 20-45% | Moderate |
| Consulting / services | 50-70% | High |
Typical gross profit margins vary widely by sector. Net margins are lower after overheads.
Frequently asked questions
What is the formula for price per unit?
Price per unit = Total cost / Quantity. If you pay $30 for a box of 10 items, the price per unit is $30 / 10 = $3.00. The inverse gives total cost: Total cost = Price per unit × Quantity.
How do I work out how many units I can afford?
Divide your budget by the unit price: Quantity = Budget / Price per unit. For example, with $50 and a unit price of $4, you can buy $50 / $4 = 12.5 units, meaning 12 whole units with $2 left over. Use the "Find quantity" mode in this calculator.
What is the difference between profit margin and markup?
Profit margin is profit divided by the selling price (revenue). Markup is profit divided by the cost price. A product that costs $6 and sells for $10 has a $4 profit: margin = 4/10 = 40%, markup = 4/6 ≈ 66.7%. Always clarify which metric a price is quoted in to avoid under-pricing.
How do I compare two products with different pack sizes?
Calculate the unit price for each: divide the total price by the number of units in the pack. Whichever pack has the lower unit price gives you more for your money. The "Compare two products" mode does this automatically and shows you the saving per unit.
What is a good profit margin?
It depends heavily on the industry. Software and consulting businesses often achieve gross margins above 60-70%, while grocery retail may run on 2-5% margins, relying on volume. For most small retail and e-commerce businesses a gross margin above 30% is considered healthy, but you also need that margin to cover operating costs and still leave a net profit.