Online Marketplace Break-Even Analysis: Month 18 Profit Path

Fixed costs $6.7K/mo Monthly overhead

Contribution margin 85% After variable costs

Break-even revenue $7.9K/mo Monthly target

Break-even timing Month 18 Model breakeven

Break-even calculator

Test whether monthly revenue covers variable expenses and fixed costs, with this model reaching break-even around Month 18.

Lean Base Full

Monthly revenue Revenue is the cash inflow that must first cover direct costs and then fixed overhead. $ Low sales High sales Variable expenses These rise with sales, like ad spend, support, and payment processing costs. $ Light costs Heavy costs

Money available to cover fixed costs $35,700 $42,000 revenue - $6,300 variable expenses

Margin ratio

85%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly overhead the contribution margin has to cover. $ Low overhead High overhead

Break-even chart Revenue Total costs

Which expenses stay fixed, and which move with orders, sellers, and buyer traffic?

Cost classification

Break-even is only useful when each expense sits in the right bucket. The model reaches break-even in Month 18, but misclassifying traffic-linked fees or step hires can make that date look safer than it is.

Expense	Cost	Break-Even Treatment	Common Mistake
Office Rent ($2,500/month)	Fixed	Include the full monthly amount before contribution covers overhead.	Spreading rent per order too early.
Cloud Hosting (fixed, $1,500/month)	Fixed	Hold flat across the monthly planning range.	Treating every cloud dollar as fixed.
Software Licenses ($800/month)	Fixed	Include as recurring overhead from Month 1 through Month 60.	Leaving recurring tools out of overhead.
Payment Gateway Fees (2.5% in first year)	Variable	Deduct from each revenue dollar when calculating contribution margin.	Modeling processing fees as monthly overhead.
Cloud Infrastructure (variable, 1.5% in first year)	Variable	Scale with buyer traffic, orders, and platform usage.	Bundling it with fixed hosting.
Digital Advertising (performance, 8.0% in first year)	Variable	Link to sales volume, separate from annual acquisition budgets.	Classifying all marketing the same way.
Customer Support workload (3.0% transaction-related spend plus support lead from Month 19)	Semi-variable	Model ticket-driven spend with orders, then add coverage as volume rises.	Treating support as pure overhead.
Software Engineer ($100,000 salary; added in second year)	Semi-fixed	Add in staffing steps as capacity needs rise.	Spreading engineering evenly per transaction.

How does break-even shift from a lean launch to full scale in this marketplace?

Scenario table

Break-even rises as fixed staff and acquisition spend rise. CAC discipline and repeat orders matter, but only if seller liquidity stays healthy.

Planning cases only; actual break-even will move with seller liquidity, repeat orders, and CAC.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch	$54,941	$8,241	$46,700	85.0%	$0	Thin cushion; CAC or support slippage can break it.
Base marketplace	$97,087	$13,689	$83,400	85.9%	$0	This is the hinge point; repeat orders and CAC discipline decide it.
Full scale marketplace	$240,406	$27,406	$213,000	88.6%	$0	Better cushion, but only if seller supply keeps up.

What breaks the break-even plan for this online marketplace?

Stress test

This plan breaks first on top-line misses: a 20% revenue shortfall or a 15% jump in fixed costs pushes break-even out fast. The main warning signs are weak traffic, a lower take rate, fraud load, and more support tickets.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change from the launch plan.	$55,000	$0 cushion	Traffic and take rate have to hold.
Revenue shortfall	Monthly revenue lands 20% below plan.	$55,000	$9,300 gap	A traffic miss leaves the model short each month.
Fixed-cost increase	Fixed costs step up 15% too early.	$63,200	$8,200 gap	Early hiring or overhead raises the break-even bar fast.
Margin pressure	Variable expense rate rises from 15% to 20%.	$58,400	$3,400 gap	Fee drag and support load eat into contribution.
Combined pressure	Revenue is 20% below plan, fixed costs rise 15%, and variable expense rate moves to 20%.	$67,100	$18,600 gap	Weak demand and cost creep can push break-even well past the launch target.

Can you prove supply, demand, and order economics before you fund the marketplace build?

Founder checklist

Don’t push major platform spend until the seller side, buyer side, and unit economics all clear the break-even math. For this model, the Year 1 mix, the $20 buyer CAC, the $150 seller CAC, and the $260K cash cushion need to hold before scale.

1Seller supply60/30/10

Verify you can recruit the Year 1 seller mix at a $150 CAC before adding more build spend, because supply comes first in a marketplace.

2Buyer demand70/25/5

Verify the Year 1 buyer mix at a $20 CAC before paid scale, because casual users alone do not carry repeat volume.

3Order take$4.20-$14.40

Check that the 12% commission on $35, $60, and $120 orders leaves room after the 4.0% COGS and 11.0% variable spend.

4Fixed burn$34.2K/mo

Year 1 fixed load is about $34.2K a month before variable costs, so launch volume has to cover that burn and the $150K platform build.

5Cash buffer$260K

Keep at least the modeled $260K cash cushion, because break-even lands in Month 18 and payback takes 31 months.

6Ops stackPre-launch

Put payment, moderation, fraud review, refund, and support workflows in place before ramp-up, or trust problems will hit cost and conversion.