Purple Martin House Break-Even: $269K Monthly Revenue

Fixed costs $21.6K/mo Base burn

Contribution margin 80.5% After variable costs

Break-even revenue $26.9K/mo Monthly target

Break-even timing Month 17 Forecast crossover

Break-even calculator

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

Lean Base Full

Monthly revenue Revenue is the pool that has to cover variable and fixed costs. $ Low sales High sales Variable expenses These are direct costs that rise with each sale, like inventory and shipping. $ Low costs High costs

Money available to cover fixed costs $32,277 $39,750 revenue - $7,473 variable expenses

Margin ratio

81%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly overhead the margin has to cover even if sales stay flat. $ Lower overhead Higher overhead

Break-even chart Revenue Total costs

Which expenses are fixed, and which move with birdhouse sales?

Cost classification

Classify inventory and shipping as variable, base overhead as fixed, and payroll as semi-fixed. Keep one-time capex out of monthly contribution margin, or Month 17 break-even math will mix build-out spend with operating economics.

Expense	Cost	Break-Even Treatment	Common Mistake
Wholesale Inventory Procurement	Variable	Apply 14.5% of first-year revenue. On $172,000 revenue, that is about $24,940 tied directly to sales.	Treating product procurement like fixed overhead instead of a sales-linked margin item.
Shipping and Fulfillment Fees	Variable	Apply 5.0% of first-year revenue. On $172,000 revenue, that is about $8,600 that rises with shipped orders.	Burying fulfillment fees in fixed operations and overstating contribution margin.
Warehouse Lease	Fixed	Use $3,500 per month, or $42,000 per year, in fixed overhead for the relevant planning range.	Allocating lease expense per unit and making break-even look lower than it is.
E-commerce Platform Subscription	Fixed	Use $450 per month, or $5,400 per year, as recurring platform overhead.	Adding it only when order volume grows, even though it starts in Month 1.
Digital Marketing Agency Retainer	Fixed	Use $2,200 per month, or $26,400 per year, as baseline operating overhead.	Modeling the full retainer as variable customer acquisition spend.
Utility and Insurance	Fixed	Use $800 per month, or $9,600 per year, unless the model adds a separate usage-based charge.	Linking the full amount to shipments without data showing usage-based billing.
Professional Conservation Partnership Fees	Fixed	Use $500 per month, or $6,000 per year, as recurring overhead from Month 1 through Month 60.	Leaving it below the line because it sounds non-operating.
Payroll	Semi-fixed	Use $170,000 in first-year salaries, then step up as support and fulfillment staffing increase with volume.	Treating all labor as per-order variable, or freezing headcount after launch.

How does break-even shift from lean to base to full in purple martin house sales?

Scenario table

Lean stays below break-even because the fixed base is still too heavy for Year 1 traffic. Base gets close as revenue scales, and full turns the model into a clear profit engine once overhead is spread across more orders.

Planning case only; actual results will move with traffic, product mix, and fulfillment costs.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean colony test	$14.3K	$2.8K	$21.6K	80.5%	-$12.3K	Below break-even; demand is still thin.
Base repeatable store	$39.8K	$7.5K	$26.2K	81.2%	$2.5K	Near break-even; small traffic swings matter.
Full expanded assortment	$112.8K	$20.4K	$31.4K	81.9%	$55.6K	Clear cushion; growth can fund more staff.

What pushes this purple martin house retailer back above break-even?

Stress test

The plan is most exposed to slower conversion, higher freight, and fixed costs that creep above the $216K monthly base. A 10% sales miss creates about a $27K monthly gap, and combined pressure can lift break-even to roughly $315K/month.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	Fixed costs stay at $216K/month and contribution margin holds at 80.5%.	$269K/month	$0 gap	Base case sits right on break-even.
Revenue shortfall	Sales run 10% below the break-even run rate.	$269K/month	$27K gap	A modest sales miss removes the cushion fast.
Fixed-cost pressure	Monthly fixed costs rise 10% to about $238K.	$295K/month	$26K gap	Lease, labor, or agency creep lifts the bar.
Margin pressure	Variable expenses rise from 19.5% to 24.5% of sales.	$286K/month	$17K gap	Freight and fulfillment pressure eat contribution.
Combined pressure	Fixed costs rise 10% and variable expenses rise to 24.5% of sales.	$315K/month	$46K gap	Discounting and cost creep push break-even far higher.

What should you verify before signing the warehouse lease and marketing retainer for purple martin house sales?

Founder checklist

Before you commit to the lease and ad spend, prove the model can hold 220 to 350 weekday visitors, convert at 1.8%, and support about $429 AOV with strong unit margin. If those checks miss, break-even slips and the fixed load lands too early.

1Traffic Proof220-350/day

Verify weekday traffic stays in the 220 to 350 visitor range and still converts at 1.8%, because that is the demand base behind Year 1 revenue and a miss here pushes break-even back.

2Fixed Load$21.6K/mo

Add the $3,500 lease, $450 platform, $2,200 marketing retainer, $800 utilities and insurance, $500 conservation fee, and about $14.2K per month of Year 1 payroll; if the gross margin won’t cover that load, don’t sign yet.

3Unit Margin80.5% CM

Here’s the quick math: the Year 1 mix and 1.3 units per order point to about $429 AOV, and 14.5% procurement plus 5.0% shipping leaves about 80.5% contribution margin before payroll and fixed costs.

4Staffing Ramp3 Year 1 roles

Keep Year 1 to the general manager, customer support, and fulfillment roles, and don’t add the Month 13 content and community hire until packing and shipping volume justify it.

5Ad Spend$2.2K/mo

Test the $2,200 monthly marketing retainer against real traffic and 1.8% conversion before you scale spend, because weak lead flow will push break-even out.

6Cash Cushion$712K

Hold enough cash to cover the modeled $712K minimum by Month 24, since Year 1 EBITDA is negative $147K and payback doesn’t land until Month 31.