The rule in one line
Keystone price = Cost × 2
Doubling the cost is a 100% markup, which works out to a 50% margin. Those are the same decision described two ways — if that sounds confusing, the margin vs markup guide explains exactly why.
Keystone pricing
The oldest rule in retail: double your cost to get your price. Simple, fast, and a decent starting point — as long as you know its limits.
Pros and cons
Pros
- Fast and easy to apply
- Builds in a healthy 50% margin
- Consistent across a whole range
- Good default when you lack market data
Cons
- Ignores demand and competition
- Can overprice commodities
- Can underprice unique items
- Doesn’t account for marketplace fees
Use it as a starting point, not the answer
Keystone gives you a defensible baseline in seconds. From there, adjust for what the market will bear and for any platform fees, then confirm the real margin with the profit margin calculator. For the full pricing workflow, see how to price a product.
Pricing & margin guides
How to Calculate Profit Margin
The profit margin formula explained with step-by-step worked examples.
Margin vs Markup
Why they're not the same, the formulas for each, and a conversion table.
How to Price a Product
A step-by-step pricing method that protects your margin from day one.
What Is a Good Profit Margin?
Healthy margin benchmarks by industry and how to know where you stand.
How to Calculate Break-Even Point
The break-even formula, contribution margin, and how many units you must sell.
Cost of Goods Sold (COGS)
What counts as COGS, what doesn't, and the formula to calculate it.
Gross Profit vs Net Profit
The difference between the two, with a worked income-statement example.
Average Order Value (AOV)
The AOV formula, why it matters, and proven ways to increase it.
How Discounts Affect Profit Margin
Why a small discount cuts profit hard, and the extra volume needed to break even.
Contribution Margin
What contribution margin is, the formula, and how it drives break-even.
Fixed vs Variable Costs
The difference, why it matters for pricing, and how to classify your costs.
Retail vs Wholesale Pricing
How to price for both channels without eroding your retail margin.
How to Calculate ROI
The return on investment formula with worked examples for stock and ads.
How to Increase Profit Margin
Ten practical, tested ways to widen your margin without losing sales.
More free calculators
Profit Margin Calculator
Sale price, margin, markup, or cost — four modes for any scenario.
Etsy Profit Calculator
Net profit after Etsy listing, transaction, payment, and Offsite Ads fees.
Amazon FBA Profit Calculator
Net profit, margin and ROI after Amazon referral, fulfillment and storage fees.
eBay Profit Calculator
Net payout after eBay's final value fee, per-order charge and international fees.
Shopify Profit Calculator
Real profit per sale after Shopify payment processing, surcharges and plan share.
Frequently asked questions
What is keystone pricing?
Keystone pricing is a simple retail rule of doubling the cost of a product to set its selling price. Buy for $10, sell for $20. That's a 100% markup, which equals a 50% profit margin.
Is keystone pricing a 100% markup or a 50% margin?
Both — they're two ways of describing the same doubling. Doubling the cost is a 100% markup (profit ÷ cost), and because the profit is half the sale price, it's a 50% margin (profit ÷ sale price). See our margin vs markup guide for why the two numbers differ.
Is keystone pricing still relevant?
It's a useful starting point and rule of thumb, but rarely the final answer. In competitive or online markets a flat 100% markup can be too high or too low. Many retailers use keystone as a baseline, then adjust up for exclusive items and down for commodities.
What are the downsides of keystone pricing?
It ignores demand, competition and your actual costs beyond the unit price. On marketplaces, a 50% margin before fees can shrink to a thin margin after Etsy, Amazon or eBay take their cut, so keystone pricing can quietly leave you underpriced.
When should you charge more than keystone?
Charge above keystone for unique, handmade, premium or hard-to-find products where customers aren't comparing on price. Charge below it for commodities in crowded markets, or where high volume at a smaller margin is more profitable overall.