Marketplace Profit After Fees Calculator

About the Marketplace Profit After Fees Calculator

Understanding your true profit per sale requires accounting for every cost: COGS, platform commission, payment processing, shipping, and advertising. This generic calculator works for any marketplace or e-commerce platform, letting you input each cost component separately.

Many sellers look at their sale price minus product cost and think that's their profit. In reality, platform fees, payment processing, shipping, and advertising typically consume 20–50% of the sale price on marketplaces. This calculator reveals the actual number.

Enter your specific fee rates and costs to get an accurate profit analysis. The results show net profit, margin, ROI, and a breakdown of where every dollar goes. Use it to evaluate whether a product is worth selling and to find the minimum viable sale price.

When This Page Helps

This is a universal profit calculator that works for any platform. Instead of using separate calculators for Amazon, eBay, and Etsy, you can enter whatever fee rates apply to the channel you are evaluating.

How to Use the Inputs

1. Enter the sale price.
2. Enter the cost of goods sold (COGS).
3. Enter the platform fee percentage.
4. Enter the payment processing fee percentage and fixed fee.
5. Enter shipping cost and advertising cost per unit.
6. Review net profit, margin, and cost breakdown.

Example Calculation

Tips & Best Practices

• Include ALL costs, even small ones like packaging — they add up across thousands of units.
• Calculate ad cost per unit by dividing total monthly ad spend by units sold.
• Target a minimum 20% margin after all deductions to sustain a healthy business.
• Run this calculation before sourcing — if margins are too thin at your target price, pass on the product.
• Revisit the calculation quarterly as costs and fee structures change.
• Compare results at different price points to find the optimal revenue-vs-volume balance.

Breaking Down E-commerce Unit Economics

Unit economics is the profit or loss per single unit sold. It is the most important metric in e-commerce because it tells you whether growth is profitable or just scales losses. This calculator helps you understand your unit economics by decomposing every cost.

The Fee Stack Problem

Marketplace sellers face a "fee stack" — multiple fees applied to the same transaction. A 15% referral fee plus 3% payment processing plus FBA fees means Amazon takes $8‒12 from a $30 product before you count COGS or advertising. Understanding this stack is essential for pricing.

Minimum Viable Selling Price

To find your minimum price, add all per-unit costs (COGS + shipping + packaging) and divide by (1 − total fee rate − target margin). For example, $12 all-in cost with 20% fees and 25% target margin: minimum price = $12 / (1 − 0.20 − 0.25) = $21.82.

Frequently Asked Questions

• What is COGS?

  Cost of Goods Sold (COGS) is the direct cost of producing or purchasing the product you sell. It includes the product purchase price, manufacturing costs, and any direct costs to get the product ready for sale, but not overhead or marketing.

• Should I include my time as a cost?

  For an accurate profit picture, yes. If you spend 15 minutes per order on customer service, packing, and shipping at $30/hour, that's $7.50 per order in labor. This is especially important for small sellers who do everything themselves.

• What is a typical all-in fee rate on Amazon?

  Amazon's combined referral fee plus FBA fulfillment typically totals 25‒35% of the sale price. Add advertising (5‒15% of revenue for most sellers) and the all-in platform cost can reach 35‒45% of revenue.

• How do I calculate advertising cost per unit?

  Divide your total advertising spend for a period by the number of units sold. For example, $1,000 in monthly ads divided by 200 units = $5 per unit. Include all ad channels: PPC, social media, influencer, etc.

• What margin should I target for e-commerce?

  Healthy e-commerce businesses typically achieve 15‒35% net margin after all costs. Margins below 10% are risky — small changes in fees, returns, or costs can eliminate profits. High-margin products (30%+) provide a buffer for scaling and testing.

• How do returns affect profit calculations?

  Returns reduce effective revenue and add costs: return shipping, restocking time, potential product damage, and non-refundable fees. For a 10% return rate, multiply your per-unit profit by 0.9 and subtract return-related costs for a more accurate profit estimate.