Legionella Prevention Service Break-Even Revenue: About $75K/Month

Fixed costs $58.3K/mo Base overhead

Contribution margin 91.5% After variable spend

Break-even revenue $63.8K/mo Revenue threshold

Break-even timing Month 4 Launch ramp

Break-even calculator

Test monthly revenue, variable expenses, and fixed costs against monthly break-even for a Legionella prevention service.

Lean Base Full

Monthly revenue Revenue is the cash that has to cover variable cost and then fixed overhead. $ Low volume High volume Variable expenses These are direct costs that rise with service volume, like lab testing and sales processing. $ Light costs Heavy costs

Money available to cover fixed costs $492,177 $532,083 revenue - $39,906 variable expenses

Margin ratio

93%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly cost base that contribution margin has to cover. $ Lean overhead Heavy overhead

Break-even chart Revenue Total costs

Which expenses stay fixed, and which move with sales in a Legionella prevention service?

Cost classification

Break-even is only useful if stable overhead stays fixed and job-driven spend flexes with revenue. Here, lab kits at 4.5% of first-year revenue and commissions at 4.0% change the break-even point faster than rent.

Expense	Cost	Break-Even Treatment	Common Mistake
Commercial Office Rent	Fixed	Include $5,500/month in fixed overhead from Month 1 through Month 60.	Letting rent rise with revenue instead of keeping it stable.
Cloud Infrastructure and Dashboard Hosting	Fixed	Include $1,200/month as fixed platform overhead before volume costs.	Treating the full hosting bill as per-customer usage.
Professional Liability Insurance	Fixed	Include $1,800/month as required monthly overhead.	Leaving insurance out because it does not touch each job.
Laboratory Analysis and Testing Kits	Variable	Apply 4.5% of revenue in the first year, falling to 3.5% by the mature year.	Treating lab fees as overhead instead of job-driven spend.
Sales Commissions and Processing	Variable	Apply 4.0% of revenue in the first year, falling to 3.0% by the mature year.	Excluding payment and sales fees from break-even math.
Senior Field Technician Payroll	Semi-variable	Include base payroll, then add overtime or extra route coverage as job volume rises.	Modeling all technician pay as fixed through growth.
Fleet Vehicle Insurance and Maintenance	Semi-fixed	Carry $2,500/month until another vehicle block is needed to cover more routes.	Ignoring travel drag when service density is low.
Annual Marketing Budget	Semi-fixed	Include planned spend blocks, starting at $120,000 in the first year.	Putting launch marketing outside break-even.

How does break-even change across lean, base, and full service books for this water safety business?

Scenario table

Lean is near break-even, base has a solid cushion, and full has the widest one. Better technician use, more advanced and premium work, and tighter routes spread fixed overhead across more billed work.

Planning assumptions only; actual results will move with sales mix, route density, and technician use.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean break-even book	$74.7k	$6.4k	$68.3k	91.5%	$0	Almost no cushion; one soft month can slip below break-even.
Base Year 1 book	$169.4k	$14.4k	$68.3k	91.5%	$86.7k	Month 4 break-even leaves room if route density holds.
Full Year 2 book	$355.3k	$28.4k	$68.3k	92.0%	$258.5k	High revenue and 92.0% CM give a wide cushion.

What pushes this Legionella prevention plan past break-even?

Stress test

Month 4 break-even holds in the base case, but the cushion is thin. Lost recurring accounts, higher lab fees, extra travel, and overtime can push breakeven past target fast.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change from the base case.	$74,700	$0 gap	Break-even lands in Month 4.
Revenue shortfall	Revenue falls 10% to about $67,200.	$74,700	$6,800 gap	A delayed renewal quickly eats the cushion.
Fixed-cost pressure	Monthly overhead rises 10% to about $75,167.	$82,150	$7,450 gap	Higher rent, insurance, or fleet cost pushes breakeven out.
Margin pressure	Variable expenses rise from 85% to 105% of revenue.	$76,350	$1,650 gap	More lab work, fuel, and overtime thin the margin.
Combined pressure	Revenue falls 10%, overhead rises 10%, and the mix shifts toward basic subscriptions.	$84,000	$16,800 gap	Lost recurring accounts and more emergency callouts can break the Month 4 path.

Should you commit to fleet, lab, and office spend before this water safety service proves break-even readiness?

Founder checklist

Confirm demand, technician capacity, workflow, and cash before you lock in bigger spend. The model reaches break-even in Month 4, but that only holds if signed work, direct costs, and launch setup stay close to plan.

1Demand proof$2.0M Y1

Confirm signed or near-signed work can support the first-year revenue path, or the Month 4 break-even target is too soft.

2Field capacity2.0 FTE

Make sure 2 senior field technicians can handle recurring monitoring, sampling, treatment, and remediation before you add routes.

3Build spend$345K

Stage the fleet, lab, kit, IT, and furniture spend against signed or near-signed work, not just a launch plan.

4Rent test$5.5K/mo

Only take the monthly office lease if it helps book and serve work fast enough to protect break-even.

5Unit margin91.5% CM

Verify the direct-cost load stays near 8.5% of revenue, because a small slip in lab or sales costs pushes break-even out.

6Cash runway$610K

Lock sample collection, lab process, insurance, dashboard hosting, and route scheduling before launch, and keep the cash trough funded through Month 4 to stay on the 10-month payback path.