Amazon FBA Break-Even Analysis: About $16K Monthly Sales

Fixed costs $11.9K/mo Overhead plus payroll

Contribution margin 80.2% After variable costs

Break-even revenue $14.8K/mo Revenue to cover

Break-even timing Month 33 Forecast crossover

Break-even calculator

Use this calculator to test monthly revenue, variable expenses, and fixed monthly costs against break-even.

Lean Base Full

Monthly revenue Revenue is the pool that pays variable costs and then helps cover fixed costs. $ Slow sales Strong sales Variable expenses Use direct costs that rise with sales, like inventory, fees, ads, and returns. $ Low direct cost High direct cost

Money available to cover fixed costs $75,900 $90,000 revenue - $14,100 variable expenses

Margin ratio

84%

Covers fixed costs

Yes

Fixed monthly costs Use the monthly overhead that sales must cover even when orders slow down. $ Lean overhead Heavy overhead

Break-even chart Revenue Total costs

Which expenses are fixed and which move with sales in this marketplace fulfillment business?

Cost classification

Break-even is only useful if unit-driven costs stay variable and monthly overhead stays fixed. Here, first-year revenue-linked operating costs total 19.8% of sales, while recurring fixed overhead starts at $2,100/month before payroll.

Expense	Cost	Break-Even Treatment	Common Mistake
Cost of Inventory	Variable	Use 7.0% of first-year revenue.	Don’t treat inventory as free cash once purchased.
Marketplace Fulfillment & Referral Fees	Variable	Use 8.0% of first-year revenue.	Don’t bury fulfillment fees in gross margin without review.
Marketplace PPC Advertising	Variable	Use 4.0% of first-year revenue.	Don’t confuse PPC with the separate $10,000 first-year marketing budget.
Payment Processing & Returns	Variable	Use 0.8% of first-year revenue.	Don’t ignore refund drag.
Software Subscriptions	Fixed	Use $800/month from Month 1 to Month 60.	Don’t scale it with every order.
Professional Services	Fixed	Use $500/month from Month 1 to Month 60.	Don’t tie advisor spend directly to unit volume.
Travel & Conferences	Semi-fixed	Use a $200/month planning allowance.	Don’t treat travel as revenue-linked spend.
Payroll	Semi-fixed	Use $117,500 in first-year annual payroll.	Don’t model planned hires as variable per unit.

How does break-even shift from a lean launch to a base build and a full-scale catalog?

Scenario table

Break-even climbs as payroll and marketing scale up, even though lower fee rates help. The lean case is easiest to fund, the base case is the main operating model, and the full case needs the widest monthly sales cushion.

Planning assumptions only: these figures show modeled break-even pressure, not a guaranteed outcome.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch case	$159k	$32k	$127k	80.2%	$0	Lowest cash load, but sales still need to clear about $159k a month.
Base operating case	$338k	$56k	$282k	83.4%	$0	Main operating case; it only stays even if monthly sales hold near $338k.
Full scale case	$422k	$57k	$365k	86.6%	$0	Best margin cushion, but the larger team means revenue must stay strong.

What breaks first if sales miss plan or fees creep up?

Stress test

Year 1 breaks even near $159k in revenue on $127k of fixed costs. The weak spots are a sales miss, a 5-point hit from pay-per-click ads, returns, storage, or fees, and any $2k monthly rise in overhead.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$159k	$0 cushion	No buffer; any miss shows up fast.
Revenue shortfall	Sales fall to $128k, about 20% below break-even.	$159k	$31k gap	That miss turns into about a $25k operating loss.
Fixed-cost pressure	Fixed costs rise by $2k a month to $129k.	$184k	$25k gap	Overhead growth pushes break-even out of reach.
Margin pressure	Ad, return, storage, and fee drag adds 5 margin points.	$169k	$10k gap	Small fee creep forces more sales just to stand still.
Combined pressure	Sales fall to $128k, margin drops to 75.2%, and fixed costs rise to $147k a month.	$196k	$51k gap	Cash burn widens fast and reorder timing gets risky.

Can you fund inventory, ads, overhead, and reorders until break-even?

Founder checklist

Test the launch against the model, not the sales pitch: Year 1 carries a 7.0% inventory cost, 8.0% marketplace fees, 4.0% PPC, and 0.8% payment friction. Break-even lands in Month 33, so cash has to survive the gap.

1Cash runway$474K floor

Verify you can still hold the $474K minimum cash floor by Month 35 while waiting for Month 33 break-even; if you cannot fund that gap, every extra reorder speeds the burn.

2Unit margin80.2% CM

Check that the Year 1 mix still leaves about 80.2% contribution margin after 7.0% inventory cost, 8.0% fees, 4.0% PPC, and 0.8% payment friction, because that margin funds the fixed load.

3Fixed burn$11.9K/mo

Verify the first-year fixed load stays near $11.9K a month from the listed overhead and the founder plus half-time sourcing role, because thin sales density cannot carry extra headcount yet.

4Launch capex$25K

Confirm you can spend the full $25K on equipment, creative assets, design, trademark, the website, quality control, and analytics before launch without starving inventory buys.

5Demand mix30/30/20/20

Test whether the first-year product mix can hold at 30% smart home, 30% office, 20% kitchen, and 20% pet, since that mix underpins pricing, ad focus, and reorder plans.

6Hire gateMonth 13/25

Keep the marketing and operations hires gated until cash receipts can pay for them; the plan adds those roles in Month 13 and data support in Month 25, so weak sales should push hiring back.