BSL-2 Laboratory Break-Even Analysis: $133K Monthly Revenue

Fixed costs $83.2K/mo Overhead + salaries

Contribution margin 70.5% After variable costs

Break-even revenue $118.0K/mo Monthly target

Break-even timing Month 7 Model ramp point

Break-even calculator

Test monthly revenue, variable expenses, and fixed costs for a specialized lab contractor.

Lean Base Full

Monthly revenue Revenue is the cash engine that pays variable costs and fixed overhead. $ Low revenue High revenue Variable expenses These are direct project costs that rise as work volume rises. $ Low direct High direct

Money available to cover fixed costs $226,330 $314,833 revenue - $88,503 variable expenses

Margin ratio

72%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly cost base break-even has to cover. $ Lean overhead Heavy overhead

Break-even chart Revenue Total costs

Which Biosafety Level 2 lab contractor expenses are fixed, variable, semi-variable, or semi-fixed?

Cost classification

Break-even gets reliable only when each expense follows the right behavior. Treat subcontractor fees and equipment procurement as revenue-linked, but keep lease, insurance, software, and base salaries in fixed overhead.

Expense	Cost	Break-Even Treatment	Common Mistake
Office Lease	Fixed	Use $12,500 per month in fixed overhead from Month 1 through Month 60.	Tying rent to project revenue instead of capacity.
Professional Liability Insurance	Fixed	Use $4,500 per month as recurring fixed overhead.	Modeling insurance as a percent of each job.
CAD and BIM Software Subscriptions	Fixed	Use $2,200 per month in fixed operating overhead.	Dropping recurring software below operating break-even.
Core Salaried Roles	Fixed	Include base salaries for the principal engineer, architect, design engineer, business development manager, and administrative assistant.	Spreading base payroll only across billable jobs.
Specialized Subcontractor Fees	Variable	Model at 15.0% of first-year revenue, falling to 13.0% by the mature year.	Treating subcontractor fees as overhead; that hides margin risk.
Laboratory Equipment Procurement	Variable	Model at 8.0% of first-year revenue, falling to 6.0% by the mature year.	Counting pass-through equipment spend as fixed overhead.
Project Travel and Site Inspections	Variable	Model at 4.0% of first-year revenue, falling to 3.2% by the mature year.	Using one flat travel budget as active projects rise.
Senior Project Manager Salary	Semi-fixed	Add salary in steps: one FTE first year, two FTEs in Year 3, and three FTEs in the mature year.	Averaging the next manager across all jobs too early.

How does break-even change from a lean to a full BSL-2 lab mix?

Scenario table

As the mix shifts from lean consulting to more turnkey and support hours, margin coverage improves and fixed costs are easier to absorb. Each customer month carries 320 turnkey hours, 40 consulting hours, and 15 maintenance hours, so utilization is the break-even lever.

Planning assumptions, not guarantees; actual margins move with project mix, staffing, and close timing.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean first-year project mix	$161.9k	$47.8k	$83.2k	70.5%	$30.9k	Thin cushion; one slipped project can erase profit.
Base year-two project mix	$314.8k	$88.5k	$83.2k	71.9%	$143.1k	Healthy cushion; fixed overhead is covered with room to grow.
Full mature-year project mix	$658.8k	$157.5k	$139.5k	76.1%	$361.9k	Strong cushion; recurring work makes overhead easier to absorb.

What pushes this BSL-2 lab plan past break-even?

Stress test

Year 1 has a cushion, but it’s not wide. A revenue slip, heavier payroll, or thinner delivery margin can erase it fast, especially if permits drag, change orders dilute fees, or senior staff sit idle.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$1,416,000	$527,000 cushion	Month 6 cash is the pinch point before Month 7 break-even.
Revenue shortfall	Year 1 revenue slips to $1,328,000.	$1,416,000	$88,000 gap	A modest start delay is enough to miss break-even.
Fixed-cost increase	Year 5 FTE levels arrive in Year 1.	$2,374,000	$431,000 gap	More senior staff before demand catches up pushes break-even above plan.
Margin pressure	Variable delivery load rises from 29.5% to 34.5% of revenue.	$1,525,000	$418,000 cushion	Change-order dilution or rework can eat most of the cushion.
Combined pressure	Year 5 FTE levels arrive early and variable load rises to 34.5%.	$2,556,000	$613,000 gap	Launch delay plus margin slip pushes break-even well above Year 1 plan.

Can the first lab projects carry the lease, staff, and cash gap before you commit?

Founder checklist

Don’t commit to the lease until the pipeline can carry the $21.6K monthly fixed load, the 70.5% project margin, and the Month 6 cash trough. Break-even lands in Month 7, so signed work, partner coverage, and launch spend have to line up first.

1Pipeline proof$1.943M / $125K

Verify booked work can support the Year 1 revenue path and the $125k marketing budget, because that is the demand proof behind Month 7 break-even.

2Fixed load$21.6K/mo

Make sure base overhead stays at $21.6K per month, including the $4.5K liability policy, or the lease and staff will outrun early cash.

3Project margin70.5%

Check that the mix holds a 70.5% project margin after subcontractors, equipment, travel, and commissioning fees, since that cushion has to fund payroll and fixed costs.

4Core team6 FTE / $740K

Confirm the opening six-FTE team can carry about $740K of Year 1 payroll without stretching cash, because hiring ahead of demand burns runway fast.

5Trade bench15.0% / 2.5%

Line up specialty trades and commissioning partners before you bid turnkey work, because the model assumes 15.0% subcontractor cost and 2.5% commissioning cost from day one.

6Cash runway$504K / Month 6

Keep the $504K Month 6 cash cushion, and delay discretionary equipment if signed work slips, because the $12.5K CAC and $125k marketing push land before payback.