01
Enter price and COGS
Your selling price and landed cost of goods give the gross profit — what's left before marketplace fees, fulfillment, and ads.
Product Profitability Calculator
Per-unit profit, margin, ROI, and monthly projections — fees and ads included.
Updated Reviewed by Sajid Hussain· Editor
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Why trust this calculator
Last updated
June 9, 2026
Coverage
9 markets · 8 currencies
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Calculated in-browser · no data stored
Pricing
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How profitable is each unit you sell?
Full per-unit profitability — fees, ads, returns, and projections
The product profitability calculator breaks down every cost that touches a single unit — COGS, platform fee, fulfillment, ad spend, and return costs — and shows you net profit per unit, net margin, ROI on cost, and how much you make each month. It goes beyond basic margin calculators by including the costs that platforms and Amazon third-party tools often bury.
**Why per-unit matters more than total revenue.** A product doing great sales volume can still be unprofitable per unit if platform fees, ads, and returns eat the margin. The per-unit view shows exactly which cost is the biggest drag — so you can fix it before scaling volume makes the losses worse.
**Platform fees are larger than most sellers expect.** A 15% Amazon referral fee plus a 12% FBA fee on a typical product means 27% of your selling price is gone before anything else. Adding COGS, ads, and the occasional return often leaves 10–15% net margin at best. Tracking the full cost stack per unit is the only way to know for certain.
**Return costs hit twice.** A 5% return rate costs you the return processing labor and restocking, plus the original fulfillment cost on a unit that earned no revenue. At scale this can be a meaningful drag — the calculator models both sides so returns are never invisible.
**Monthly projection and break-even.** Net profit per unit multiplied by monthly volume gives your real monthly contribution. The break-even units output tells you exactly how many units you need to sell each month to cover your fixed overheads — a practical floor for any product launch decision.
Quick facts
- Cost layers
- COGS · Platform fee · Fulfillment · Ads · Returns
- Margins
- Gross and net per unit
- Projections
- Monthly net profit at your sales volume
- Break-even
- Units / month to cover fixed costs
- ROI
- Net profit on total variable cost
- Currency
- Works in any currency
How it works
From selling price to real per-unit profit in four steps
Enter your numbers, see every cost layer and the true margin in seconds.
02
Add platform fee and fulfillment
Platform referral fee (as % of selling price) and fulfillment cost per unit are the two biggest variable costs after COGS. Enter the real numbers, not estimates.
03
Include ad spend and returns
Divide your monthly ad spend for this product by units sold to get ad cost per unit. Enter your return rate and processing cost — both reduce net profit per unit.
04
Read net profit, margin, ROI, and break-even
The calculator shows net profit per unit, net margin %, monthly net profit at your sales volume, ROI on cost, and the break-even unit count for your fixed overheads.
Steps to use the Product Profitability Calculator: Enter price and COGS, Add platform fee and fulfillment, Include ad spend and returns, Read net profit, margin, ROI, and break-even.
Formula
The math behind every output
All formulas are straightforward — no black boxes.
01
Platform fee amount
Platform Fee Amount = Selling Price × Platform Fee % ÷ 100
The actual monetary fee taken by the marketplace on each sale. Amazon referral fees, Shopify transaction fees, and eBay final value fees all work this way.
02
Return cost per unit
Return Cost / Unit = Return Rate % ÷ 100 × Return Processing Cost
Expected return processing cost amortised across all units sold. On a 5% return rate with a 3 per-unit processing cost, each unit sold carries a 0.15 return burden.
03
Total variable cost
Total Variable Cost = COGS + Platform Fee + Fulfillment + Ad Spend + Return Cost
Every cost that scales with each unit sold. Fixed overheads (software, subscriptions) are NOT included here — they appear only in the break-even calculation.
04
Net profit per unit
Net Profit / Unit = Selling Price − Total Variable Cost
The true per-unit margin after every variable cost. Can be negative if costs exceed the selling price.
05
Net margin
Net Margin % = Net Profit / Unit ÷ Selling Price × 100
Net profit expressed as a percentage of the selling price. 0% if selling price is zero.
06
ROI on variable cost
ROI % = Net Profit / Unit ÷ Total Variable Cost × 100
How much net profit you earn for every unit of cost you put in. 50% ROI means every 1 unit of cost returns 1.50 in revenue.
07
Break-even units per month
Break-even Units = ⌈Fixed Monthly Costs ÷ Net Profit / Unit⌉
The minimum units sold per month to cover your fixed overheads. Rounded up to the nearest whole unit. Only meaningful when net profit per unit is positive.
Worked example
A realistic product — cost by cost to net profit
See how every cost layer reduces a selling price to real per-unit profit.
Scenario
A product sells for $35.00. COGS is $12.00, platform fee is 15%, fulfillment $4.50, ad spend $2.50 per unit, return rate 5% with $0.15 amortised cost. Monthly volume: $200.00 units, fixed costs $500.00.
1
Step 1 · Gross profit
Selling price $35.00 minus COGS $12.00 = $23.00 gross profit per unit.
Gross profit: $23.00 per unit
2
Step 2 · Platform and fulfillment costs
Platform fee: $35.00 × 15% = $5.25. Fulfillment: $4.50. Running cost after COGS: $12.00 + $5.25 + $4.50 = $24.40 (before ads and returns).
After fees + fulfillment: margin shrinking
3
Step 3 · Ads and returns
Ad spend per unit: $2.50. Return cost per unit: $0.15 (5% rate × processing cost). Total variable cost: $24.40.
Total variable cost: $24.40 per unit
4
Step 4 · Net profit and monthly projection
$35.00 − $24.40 = $10.60 net profit per unit. At $200.00 units/month: $10.60 × $200.00 = $2,120.00. Break-even: $500.00 ÷ $10.60 = $48.00 units/month.
Net profit: $10.60/unit · $2,120.00/month · $48.00 units to break even
The takeaway
After every variable cost the product earns $10.60 per unit — a 30% net margin — and generates $2,120.00 per month at the current sales rate. Fixed costs are covered after just $48.00 units.
Industry benchmarks
What margins are realistic for ecommerce products
Benchmarks vary by category. Platform fee and fulfillment structure heavily influence where net margins land.
| Metric | Poor | Average | Good | Excellent |
|---|---|---|---|---|
Net margin per unit TrueProfit Ecommerce Benchmark Report 2026 | < 5% | 5–15% | 15–25% | 25%+ |
Gross margin per unit Shopify Merchant Profitability Study 2025 | < 30% | 30–50% | 50–65% | 65%+ |
ROI on variable cost Derived from net-margin benchmarks above | < 15% | 15–40% | 40–70% | 70%+ |
Platform fee (% of selling price) Amazon / eBay / Shopify published fee schedules 2026 | > 30% | 15–30% | 8–15% | < 8% |
Return rate Narvar Consumer Study 2025 | > 20% | 10–20% | 3–10% | < 3% |
Ad spend per unit (as % of selling price) Jungle Scout State of the Amazon Seller 2026 | > 20% | 10–20% | 5–10% | < 5% |
Why this calculator
Calcrux vs other product margin calculators
Most free tools only subtract COGS and call it profit. This one includes every variable cost — platform fee, fulfillment, ads, and returns — the way a real P&L does.
| Feature | Calcrux | Helium 10 Profitability Calculator | Basic Margin Tool |
|---|---|---|---|
| Platform fee as % of price | |||
| Fulfillment cost per unit | |||
| Ad spend per unit | Limited | ||
| Return rate and processing cost | |||
| Monthly profit projection | |||
| Break-even units calculation | |||
| ROI on variable cost | |||
| Works for any marketplace | Amazon-only | ||
| Free, no signup | Paid plan |
Common mistakes
Where product profitability math goes wrong
Treating gross margin as net margin
Why it matters
Gross margin subtracts only COGS. Platform fees (15–30%), fulfillment (3–15 per unit), and ads can eat another 20–40 percentage points, leaving a fraction of that gross margin as actual net profit.
Fix
Always model the full cost stack: COGS + platform fee + fulfillment + ad spend + return costs. This calculator does it in one step.
Forgetting to include ad spend in unit economics
Why it matters
Ad spend is often reported as a business-level line item, not a per-unit cost. But if ads drive your sales, their cost belongs in the per-unit analysis — otherwise net margin is overstated.
Fix
Divide total monthly ad spend for a product by monthly units sold to get ad cost per unit, then include it in the variable cost stack.
Ignoring return processing costs
Why it matters
A 10% return rate with a 5 per-unit processing cost adds 0.50 to the cost of every unit sold — not just the returns. At scale this silently erodes margin.
Fix
Enter your return rate and per-return processing cost. The calculator amortises this across all units automatically.
Not knowing the break-even unit count
Why it matters
A product can be profitable per unit but still not cover its share of fixed overheads (software, storage, subscriptions) at current sales velocity. Without a break-even figure you're flying blind on launch and restock decisions.
Fix
Enter your fixed monthly costs. Break-even units tells you the minimum monthly volume the product must reach to justify its overhead share.
Scaling a loss-making product to "grow into profit"
Why it matters
Variable costs scale with volume. Selling more units of a product with a negative net margin makes the loss bigger, not smaller. Fixed-cost leverage only helps when per-unit profit is positive.
Fix
Fix per-unit economics first (pricing, sourcing, ad efficiency). Scale only when net profit per unit is clearly positive.
Tips
Get the most from per-unit profitability analysis
Update ad spend monthly
Ad cost per unit changes as your bids, conversion rate, and seasonal competition shift. Recalculate whenever your ACOS or ROAS changes meaningfully.
Use platform-specific fee schedules
Amazon referral fees vary by category (6–45%) and FBA fees depend on size tier. Use the exact numbers from your marketplace, not a blanket estimate.
Segment return rates by SKU
Return rates vary enormously by product type. Electronics and clothing return at 15–30%; commodity items often under 3%. Using a blended return rate hides the worst offenders.
Recalculate before scaling spend
Before increasing ad budget, confirm the per-unit margin at current ad spend. If margin is thin, scaling spend will amplify the problem, not solve it.
Set minimum margin pre-sourcing
Decide in advance what minimum net margin makes a product worth listing — typically 15–20% for physical goods. Use this calculator in the sourcing phase, not after launch.
Factor in seasonal fee changes
Amazon's Q4 FBA storage fees can be 4–6× higher than the off-peak rate. If you carry inventory through October–December, model the higher fulfillment cost separately for that period.
Use cases
Who reaches for this calculator and when
The Product Profitability Calculator works across every stage of the workflow.
Amazon FBA Seller
Before sourcing, plug in the expected selling price, sourcing cost, FBA fee, and ad spend to see if the per-unit margin justifies the investment.
Shopify Merchant / DTC Brand Owner
Enter the new selling price and check whether net margin and monthly profit at current volume justify the potential dip in conversion rate.
Dropshipper / Product Sourcing Lead
Hold all other inputs constant, change COGS for each supplier, and compare net margin and ROI — the one with the better margin wins.
Brand Owner / Product Manager
Monthly check-in: update ad spend per unit and return rate, and watch for net margin slipping below the 15% floor that signals a sourcing or fee issue.
Ecommerce Manager / Catalogue Owner
Use break-even units to set the minimum monthly sales velocity required before a new SKU earns its place in the catalogue.
Operations Analyst / Fulfilment Lead
Change fulfillment cost to the 3PL rate and compare net profit per unit and monthly P&L against the current FBA or in-house model.
Glossary
Per-unit profitability terms
Every important term you'll encounter in this calculator and the broader topic.
- COGS (Cost of Goods Sold)
- The landed cost per unit: product purchase price plus inbound freight, duties, and packaging. Does not include overheads or marketplace fees.
- Platform fee
- The referral, transaction, or commission fee charged by a marketplace or payment processor as a percentage of the selling price. Amazon referral fees range from 6% to 45% by category.
- Fulfillment cost
- The per-unit cost of picking, packing, and shipping the order to the customer. Includes FBA fees, 3PL charges, or in-house shipping costs.
- Ad spend per unit
- Total advertising spend for a product divided by units sold in the same period. Expresses the advertising burden as a cost that belongs in the per-unit P&L.
- Return rate
- Percentage of units sold that are returned by buyers. A 5% return rate means 5 out of every 100 units come back.
- Net margin
- Net profit as a percentage of selling price. The true per-unit margin after every variable cost — COGS, platform fee, fulfillment, ads, and returns.
- ROI on cost
- Net profit divided by total variable cost, expressed as a percentage. Measures the return on every dollar of cost you put into each unit.
- Break-even units
- The minimum units you must sell per month for a product to cover its share of fixed monthly overheads. Calculated as fixed costs divided by net profit per unit, rounded up.
- Variable cost
- A cost that scales directly with units sold: COGS, platform fee, fulfillment, ad spend, return processing. Contrast with fixed costs (subscriptions, software) that don't change with volume.
Help & answers
Frequently asked questions
Everything you need to know about how the Product Profitability Calculator works.
01How do I calculate product profitability?
Product profitability = selling price minus all variable costs per unit: COGS, marketplace fee, fulfillment, ad spend per unit, and return costs. Divide by selling price to get net margin. This calculator does all of it in one step — enter your numbers and see the result instantly.
02What costs should I include in per-unit profitability?
Include every cost that scales with each unit sold: product cost (COGS), platform referral or transaction fee, fulfillment cost (FBA, shipping, or 3PL), ad spend per unit (total monthly ad spend divided by units sold), and return costs amortised across all units. Fixed costs like software subscriptions are excluded from per-unit profit and appear only in the break-even calculation.
03What is a good net margin per unit for ecommerce?
For most ecommerce products, 15–25% net margin per unit is considered healthy. Under 10% is thin — a small cost increase can flip it to a loss. Over 25% is strong and gives room to scale ad spend. Margins vary by category: commodities run 5–15%, premium or private-label brands often 20–35%.
04How does platform fee affect per-unit profit?
Platform fees are typically 6–30% of the selling price, taken before anything else. On a 35 selling-price product with a 15% Amazon referral fee, 5.25 is gone immediately — before COGS, fulfillment, or ads. At higher percentages (clothing: 17%, electronics: up to 15%) the fee alone can make a low-price product unprofitable.
05How do I calculate break-even units for a product?
Break-even units = fixed monthly costs ÷ net profit per unit, rounded up. If you make 10.60 per unit and your fixed monthly overheads are 500, you need to sell at least 48 units per month just to cover those overheads. Below that volume the product does not pay its way.
06Why does my product seem profitable but I still lose money overall?
Two common reasons: (1) The per-unit calculation is missing a cost — typically ad spend or return processing that gets reported at the business level rather than the product level. (2) The product is profitable per unit but the volume is below break-even for its share of fixed overheads. Use this calculator with all cost inputs including ad spend per unit to find the leak.
07How do I calculate ad spend per unit?
Divide your total monthly ad spend for a specific product by the number of units that product sold in the same month. For example, 500 in ad spend for 200 units = 2.50 ad spend per unit. This turns a business-level cost into a per-unit cost that belongs in the product P&L.
08Does this calculator work for Shopify, eBay, and non-Amazon marketplaces?
Yes. Enter the actual fee percentage for your platform: Shopify charges 0.5–2% transaction fee (depending on plan) plus payment processing, eBay charges 12–15% final value fee, Etsy charges 6.5%, Walmart Marketplace 6–15%. The calculator works in any currency and for any marketplace worldwide — just use the real fee numbers from your platform.
09What costs are not included in this calculator?
This calculator covers variable costs per unit — costs that scale with each sale. It does not include annual platform subscription fees (e.g. Amazon seller account: 39.99/month), product photography or listing setup costs, or import duties (add these to your COGS). Enter platform subscriptions in the fixed monthly costs field so they appear in the break-even calculation.
10How is this different from a basic profit margin calculator?
A basic margin calculator subtracts one cost (COGS) from the selling price and calls it profit — that is gross margin, not net. This calculator stacks five cost layers — COGS, platform fee, fulfillment, ad spend, and return costs — the way a real product P&L does. It also adds monthly profit projection, break-even units, and ROI on cost, which tools like Helium 10 and SellerApp put behind a paywall.
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Category
Ecommerce Seller Operations
Subcategory
financial profitability
Availability
Global · 9 markets
Price
Free forever
Topics
product profitabilityunit economicsecommerce profitper unit profitproduct margin calculatorproduct profitability calculatornet margin per unitbreak even unitsroi on cost
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