How This Calculator Works
The break-even calculator determines the exact number of units you must sell before your cumulative revenue exceeds your total costs. It starts by calculating your fixed costs: the initial inventory order (product cost + shipping + prep per unit, multiplied by order quantity) plus one-time expenses like photography and a PPC launch budget.
Next, it computes profit per unit sold by subtracting all variable costs from the sale price. Variable costs include the Amazon referral fee (a percentage of the sale price), FBA fulfillment fees, ongoing PPC spend per unit, monthly storage costs, and an estimated return cost based on your return rate. The formula is: Break-Even Units = Total Fixed Costs / Profit Per Unit.
Time to profitability is then estimated by dividing the break-even unit count by your expected monthly sales velocity. The profit curve chart visualizes cumulative P&L at various unit milestones, and the scenario comparison models conservative, moderate, and aggressive sales assumptions so you can plan for different outcomes.
Example Scenario
Imagine you are launching a kitchen gadget on Amazon. Your product costs $6.50 per unit from your supplier, shipping to FBA runs $1.50 per unit, and prep costs $0.50 per unit. You order 500 units, spend $200 on product photography, and allocate $300 for a PPC launch campaign. Your total fixed investment is ($6.50 + $1.50 + $0.50) x 500 + $200 + $300 = $4,750.
You price the product at $29.99. After a 15% referral fee ($4.50), a $4.75 FBA fee, $2.00 PPC per unit, $0.15 storage, and an estimated return cost of $0.45 (3% return rate), your profit per unit is $29.99 - $4.50 - $4.75 - $6.50 - $1.50 - $0.50 - $2.00 - $0.15 - $0.45 = $9.64.
At $9.64 profit per unit, you break even after selling 493 units ($4,750 / $9.64). If you sell 100 units per month, that takes roughly 5 months. Every unit sold beyond 493 is pure profit.
When to Use This Tool
Run a break-even analysis before placing your first inventory order for any new product. It tells you whether the product's economics support profitability at realistic sales volumes, and it highlights which cost inputs have the biggest impact on your timeline to profit.
This tool is also valuable when renegotiating supplier pricing, adjusting your sale price, or changing your PPC strategy. Plug in the new numbers and see immediately how the break-even point shifts. Comparing the three built-in scenarios (conservative, moderate, aggressive) helps you stress-test your assumptions before committing capital.
Frequently Asked Questions
What counts as a fixed cost vs. a variable cost?
Fixed costs are expenses you pay once regardless of how many units sell, such as your initial inventory purchase, product photography, and PPC launch budget. Variable costs are incurred on every unit sold, including Amazon referral fees, FBA fulfillment fees, PPC spend per unit, and storage fees. The break-even formula divides fixed costs by profit per unit, where profit per unit is your sale price minus all variable costs.
How accurate are the FBA fee estimates?
The calculator uses Amazon's published 2026 fee schedule defaults. However, actual fees can vary based on your product's size tier, weight, category, and whether you are enrolled in programs like FBA New Selection or Small and Light. Always cross-reference the calculator's output with the fee preview in Amazon Seller Central before making final sourcing decisions.
What if my product never breaks even?
If the calculator shows "Never" for your break-even point, it means your variable costs per unit exceed your sale price, so you lose money on every sale. In that case, you need to raise your price, negotiate lower supplier costs, reduce PPC spend, or find a lower-fee fulfillment option before launching. No amount of volume fixes negative unit economics.
Should I include PPC in the break-even calculation?
Yes. Many sellers exclude PPC when evaluating product viability, but advertising is a real cost of doing business on Amazon. Including a per-unit PPC estimate gives you a more honest picture of when you will actually turn a profit. If your break-even timeline doubles when PPC is included, that is critical information for planning cash flow and inventory reorders.
How do I estimate my monthly sales velocity?
Use a product research tool like Jungle Scout or Helium 10 to check estimated monthly sales for similar products in your niche. Look at the top 5 to 10 competitors and take an average. For a conservative estimate, assume you will capture 5% to 10% of the niche leader's volume in your first 3 months. Adjust upward as you gather real data from your own listing.