Photocell Installation Break-Even: About $35k/Month

Fixed costs $21.1K/mo Year 1 base

Contribution margin 70.5% After variable costs

Break-even revenue $30.0K/mo Monthly target

Break-even timing Month 8 Launch ramp

Break-even calculator

Test monthly revenue, variable expenses, and fixed costs against the break-even point for a photocell light sensor installation business.

Lean Base Full

Monthly revenue Revenue sets the cash left after direct costs to cover overhead. $ Slow month Busy month Variable expenses These are direct material, fuel, and fee costs tied to each job. $ Low direct cost High direct cost

Money available to cover fixed costs $58,200 $80,400 revenue - $22,200 variable expenses

Margin ratio

72%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly overhead break-even has to absorb. $ Tight overhead Higher overhead

Break-even chart Revenue Total costs

Which photocell installation expenses are fixed, and which move with sales?

Cost classification

Break-even works only when job-level costs stay separate from monthly overhead. In this model, the Month 8 break-even depends on treating sensors, wiring, fuel, and card fees as volume-linked inputs.

Expense	Cost	Break-Even Treatment	Common Mistake
Warehouse and office rent	Fixed	Include $2,800 per month in fixed overhead before calculating required contribution.	Spreading rent across jobs and hiding low volume risk.
General liability insurance	Fixed	Include $650 per month as overhead that must be covered regardless of job count.	Treating insurance as a per-job charge.
CRM and scheduling software	Fixed	Include $250 per month in fixed operating overhead for dispatch and booking support.	Leaving software out because it feels small.
Electrical components and sensors	Variable	Use 18.0% of first-year revenue as job-level materials in contribution margin.	Putting sensors in overhead instead of each installation.
Installation consumables and wiring	Variable	Use 5.0% of first-year revenue as direct install usage tied to completed jobs.	Ignoring wire, connectors, boxes, and small parts.
Vehicle fuel and maintenance	Semi-variable	Model the 4.0% first-year revenue driver, then watch route spread as jobs move farther apart.	Assuming every added job has the same drive time.
Payment processing fees	Variable	Use 2.5% of revenue as a direct sales-linked fee in contribution margin.	Calculating break-even before card fees.
Annual marketing budget	Semi-fixed	Spread the $12,000 first-year budget across the year, separate from the $1,200 monthly management fee.	Confusing marketing budget with customer acquisition cost.

How does break-even shift from a lean launch to a full multi-crew install setup?

Scenario table

At launch, the business is close to break-even but still carries loss risk. As the mix shifts toward commercial, HOA, and retrofit work, the margin cushion improves, but the full crew only works if demand fills the added payroll and vehicles.

Scenario figures are planning assumptions, not guarantees.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch case	$30.6k	$9.0k	$24.6k	70.5%	-$3.0k	Break-even stays tight through Month 8.
Base scale case	$80.4k	$22.3k	$6.9k	72.3%	$51.2k	More commercial, HOA, and retrofit work gives a clear cushion.
Full multi-crew case	$144.9k	$37.5k	$7.5k	74.1%	$99.8k	The cushion is strongest, but demand must support the extra crews.

What pushes this photocell installation plan below break-even?

Stress test

This plan slips fast if sales soften, overhead rises, or sensor and wire costs climb. The biggest warning signs are a weaker commercial pipeline, more callbacks, extra fuel, and a lower close rate.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$349k/month	$0 gap	Baseline clears only if volume holds.
Revenue shortfall	Year 1 average revenue falls 10% to about $275k/month.	$349k/month	$52k gap	Slower sales can push you under break-even.
Fixed-cost increase	Add $2k/month of overhead.	$377k/month	$28k gap	Higher rent or admin cost eats the cushion.
Margin pressure	Variable load rises from 295% to 345%.	$375k/month	$26k gap	More fuel, wire, and sensor cost squeezes margin.
Combined pressure	Revenue falls 10%, variable load hits 345%, and overhead adds $2k/month.	$377k/month	$85k gap	This is the clearest break-even failure case.

Can this installer cover overhead before signing the lease, buying stock in bulk, or adding a second van?

Founder checklist

Hold the lease, bulk buys, and extra hires until booked work can support about $31K to $35K a month. Year 1 revenue is modeled at $367K, but the real test is whether margin and cash still hold through Month 24.

1Lease Cover$31K-$35K/mo

Verify booked revenue can reach this range before you lock in rent and staffing, because the fixed load starts with $2,800 rent and $650 insurance each month.

2Base Overhead$5.45K/mo

Check that recurring rent, insurance, software, utilities, marketing fees, and dues stay covered in slower months, since that is the cash floor you have to clear.

3Margin Stack70.5% CM

Make sure pricing still leaves about 70.5% after sensors, wiring, fuel, and payment fees, or each job will need too much volume to break even.

4Crew Capacity35 hrs

Confirm the opening crew can handle 35 residential billable hours per job without piling up callbacks, because rework and travel time can erase the profit.

5Cash Buffer$532K Month 24

Hold enough cash to survive the Month 24 low point and the 36-month payback window, since this model gets cash hungry before it gets steady.

6Lead Cost$150 CAC

Keep customer acquisition cost near $150 while the $12,000 Year 1 ad budget and $1,200 monthly marketing fee test demand, and tie sensor inventory to signed jobs instead of bulk buys.