Faraday Cage Design And Installation Break-Even: $124K/Month

Fixed costs $88.6K/mo Recurring burden

Contribution margin 76.5% After variable costs

Break-even revenue $115.8K/mo Revenue target

Break-even timing Month 2 Early ramp point

Break-even calculator

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

Lean Base Full

Monthly revenue Revenue is the pool that covers direct costs and overhead. $ Low sales High sales Variable expenses These are direct costs that rise with each project. $ Lean cost High cost

Money available to cover fixed costs $372,800 $537,500 revenue - $164,700 variable expenses

Margin ratio

69%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly overhead contribution margin has to cover. $ Lower overhead Higher overhead

Break-even chart Revenue Total costs

Which expenses are fixed and which move with sales for an electromagnetic shielding enclosure business?

Cost classification

Clean break-even starts by separating base monthly overhead from job-linked spend. If project materials, field work, and commissions get buried in overhead, the revenue target will look safer than it is.

Expense	Cost	Break-Even Treatment	Common Mistake
Manufacturing Facility Lease	Fixed	Carry $14,500 per month in fixed overhead from Month 1 through Month 60.	Allocating rent into unit margin and hiding unused capacity.
Simulation Software Subscription	Fixed	Include $3,200 per month below contribution margin as recurring engineering overhead.	Treating required design software as optional project spend.
Engineering Payroll	Semi-fixed	Model salaries as staffing steps tied to capacity, not as a percent of revenue.	Charging all engineering support to projects and understating base burn.
Quality Assurance Payroll	Semi-fixed	Add headcount in steps as validation volume grows across the forecast.	Assuming quality staffing rises smoothly with every sale.
Magnetic Shielding Sheets	Variable	Include the per-unit material amount in unit-level contribution margin.	Burying project materials inside overhead.
Sales Commissions	Variable	Apply 3.5% of revenue in the first three years and 3.0% after that.	Modeling commissions as fixed sales payroll.
Freight and Logistics	Variable	Apply the revenue-based rate, starting at 2.0% in the first year.	Using one flat shipping budget despite unit growth.
Site Integration Support	Semi-variable	Track job-linked support at the project level, with field workload moving as installations increase.	Folding field review and integration time into general overhead.

How does break-even shift from lean to base to full capacity in an electromagnetic shielding business?

Scenario table

Higher volume spreads engineering payroll and facility overhead across more work, so break-even moves out more slowly than revenue. The catch is timing: if installs slip, fixed costs keep running while cash comes in later.

Planning cases use the model's Year 1, Year 3, and Year 5 assumptions, so they show direction, not a promise.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch mix	$538k	$165k	$88k	69.3%	$284k	Break-even sits near $127k per month, so this case still has a cushion.
Base ramp mix	$1.08M	$319k	$125k	70.5%	$425k	Break-even is about $177k per month, and on-time delivery protects the margin.
Full capacity mix	$1.85M	$523k	$181k	71.7%	$1.15M	Break-even rises to about $252k per month, so the larger cushion depends on steady throughput.

What breaks the break-even plan when project timing slips or costs rise?

Stress test

The base plan clears break-even, but the cushion narrows fast if one shielded-room job slips, overhead rises, or labor eats 5 margin points. Watch late deposits, change orders that eat margin, idle crews, and material lead-time gaps.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$1.24M	$4.13M cushion	Healthy cushion, but Month 2 still has to hold.
Revenue shortfall	One shielded-room project slips from the first operating year.	$1.24M	$2.82M cushion	One slip removes about $1.32M of contribution.
Fixed-cost increase	Monthly overhead rises 10% from $881K to $969K.	$1.36M	$4.01M cushion	Higher overhead lifts the break-even floor.
Margin pressure	Project labor and rework cut contribution margin by 5 points.	$1.33M	$4.04M cushion	Rework and labor overruns make each job weaker.
Combined pressure	One shielded-room project slips, monthly overhead rises 10%, and margin falls 5 points.	$1.47M	$2.59M cushion	Delay, overhead, and margin loss can erase cushion fast.

Are signed orders, capacity, and test access ready before you lock in the build?

Founder checklist

The model reaches break-even by Month 2, but only if demand is already in the pipe and the shop can ship on time. Hold off on the lease, hiring, and equipment if backlog, quotes, or test access are still shaky.

1Signed backlog$6.45M Y1

Confirm signed or late-stage orders can support the first-year revenue plan before you commit to the lease and staffing base.

2Run-rate$88.1K/mo

Check that lease, software, insurance, marketing, utilities, IT, and Year 1 wages really total about this level so you know the sales floor you must clear.

3Project margin71% CM

Reprice mu-metal, copper mesh, filters, doors, gaskets, panels, sealants, freight, and commissions so each job keeps this share after variable cost.

4Shop output12/45/8/120/25

Verify the first-year team and shop can deliver this unit mix without slipping dates or forcing overtime.

5Cash floor$1.092M

Keep cash above the Month 1 minimum while you stage the $798K equipment plan, because these buys hit before revenue does.

6Test accessMonth 2

Lock in anechoic and RF test access early enough to support break-even, because late validation can stall installs and revenue.