Keystone Markup Calculator
Keystone pricing is one of the oldest rules in retail: you set the selling price at exactly double the cost of the item. It is a quick, repeatable way to price merchandise that builds a predictable gross margin into every line you carry. This calculator takes your unit cost and returns the keystone selling price, the dollar markup that price represents, and the gross margin you keep after the cost of goods is paid. The math is simple but the distinction between markup and margin trips up many sellers, so the results panel shows both side by side: keystone is a 100 percent markup on cost yet only a 50 percent margin on the sale price, because margin is always measured against what the customer pays. Use the tool to price apparel, gifts, hardware or any catalog where a fast benchmark beats a long spreadsheet, then adjust above or below keystone to match your competition and demand. The numbers here are computed deterministically from the keystone rule shown below, with a worked example that reconciles exactly to the calculator defaults so you can follow each step and trust the figure before you set your shelf tag.
Keystone pricing doubles the cost: selling price = cost x 2. A unit costing $45.00 gets a keystone price of $90.00, a markup of $45.00 and a gross margin of 50.00%.
Keystone markup formula
Selling price = Cost x 2
Markup amount = Selling price - Cost
Gross margin = Markup amount / Selling price
(a strict keystone gives a 50% margin on every item)
Doubling the cost adds one whole cost as profit, which is a 100% markup on cost. Because margin is measured against the price the customer pays, that same dollar of profit is exactly half of the selling price, a 50% gross margin.
Worked example
A boutique buys a scarf for 45 dollars and applies strict keystone pricing.
- Selling price = 45 x 2 = 90.00
- Markup amount = 90.00 - 45.00 = 45.00
- Gross margin = 45.00 / 90.00 = 0.50 = 50.00%
The keystone price is 90.00 dollars with a 50.00% margin. These are the calculator's default inputs, so the result above matches the widget exactly.
Keystone prices at common costs
Strict keystone always doubles the cost, giving a 50% margin regardless of the price point.
| Cost | Keystone price | Markup | Margin |
|---|---|---|---|
| $10.00 | $20.00 | $10.00 | 50% |
| $25.00 | $50.00 | $25.00 | 50% |
| $45.00 | $90.00 | $45.00 | 50% |
| $80.00 | $160.00 | $80.00 | 50% |
Pricing and margin basics: US Securities and Exchange Commission, Investor.gov.
Keystone markup calculator: frequently asked questions
What is keystone markup?
Keystone markup is a traditional retail pricing rule that sets the selling price at exactly twice the cost of goods. If an item costs you 45 dollars, the keystone price is 90 dollars. The practice is common in apparel, gift, jewelry and hardware retail because it is fast to apply and builds in enough gross margin to cover operating costs and profit. Keystone is a starting point, not a law: many retailers adjust above or below it based on competition and demand.
What gross margin does keystone give?
Doubling the cost always produces a 50 percent gross margin. The markup on cost is 100 percent (the price is one whole cost above the cost), but margin is measured against the selling price, so the margin is the cost divided by the price, which is one half. A 45 dollar cost sold at 90 dollars keeps 45 dollars of gross profit, and 45 divided by 90 is 50 percent.
Is markup the same as margin?
No. Markup is profit expressed as a percentage of cost, while margin is profit expressed as a percentage of the selling price. Keystone is a 100 percent markup but only a 50 percent margin. Confusing the two leads to underpricing, so always state which base you are using. This calculator shows both so you can see the gap clearly.
When should I not use keystone?
Keystone can leave money on the table for unique or premium items and can price you out of the market for commodity goods with thin margins, such as electronics or groceries. Use it as a quick benchmark, then test the price against your customers, your competitors and your true cost of doing business, including freight, shrinkage and returns.
What is the keystone markup formula?
Keystone price equals cost multiplied by 2. The markup amount is the price minus the cost, which equals the cost itself. Gross margin equals the markup divided by the price, which is always 50 percent under strict keystone pricing.
Official sources
- Pricing, margin and small-business money basics: US Securities and Exchange Commission, Investor.gov. As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.