Dumbwaiter Installation Break-Even Analysis: $44K Monthly Revenue

Fixed costs $7.5K/mo Core overhead base

Contribution margin 71% After variable costs

Break-even revenue $42.5K/mo Monthly target

Break-even timing Month 6 Model turn point

Break-even calculator

Use this to test whether monthly revenue covers variable costs and fixed overhead.

Lean Base Full

Monthly revenue Revenue is the monthly cash coming in before costs. $ Low sales High sales Variable expenses These are direct costs that rise as jobs and projects rise. $ Low cost High cost

Money available to cover fixed costs $150,000 $220,750 revenue - $70,750 variable expenses

Margin ratio

68%

Covers fixed costs

Yes

Fixed monthly costs These are the monthly overhead costs break-even has to cover. $ Lean overhead Heavy overhead

Break-even chart Revenue Total costs

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

Cost classification

Break-even gets unreliable when fixed overhead, salaried capacity, and job-linked expenses are mixed together. Here’s the quick math: classify each expense first, then apply the right monthly or revenue-based driver.

Expense	Cost	Break-Even Treatment	Common Mistake
Warehouse and Office Rent	Fixed	Include $4,200 in monthly overhead from Month 1 through Month 60.	Spreading rent only across won jobs.
General Liability Insurance	Fixed	Include $1,100 each month even when installation volume is light.	Ignoring insurance during slow months.
Lead and Junior Technician Salaries	Semi-fixed	Include salary capacity until headcount changes: $72,000 per lead technician and $48,000 per junior technician annually.	Treating salaried labor as fully variable.
Dumbwaiter Unit and Components	Variable	Use 18.0% of first-year revenue as job-linked equipment expense.	Hiding units in inventory instead of matching them to revenue.
Installation Raw Materials	Variable	Use 5.0% of revenue for installation materials in the first year.	Calling materials overhead and understating job margin.
Freight and Shipping Costs	Variable	Use 3.5% of first-year revenue, then track spikes by job size and distance.	Missing delivery spikes on larger installations.
Permitting and Site Inspection Fees	Variable	Use 2.5% of first-year revenue for permit and inspection activity.	Averaging permits too low across complex jobs.
Online Marketing Budget	Semi-variable	Use the $12,000 first-year budget and $450 customer acquisition cost to test lead flow.	Treating qualified leads as free.

How does break-even shift across lean, base, and full-capacity setups for a dumbwaiter installation service?

Scenario table

Lean leaves the business short of fixed costs, base clears them with room to spare, and full capacity opens a much wider cushion. The main swing factor is the spread between revenue and variable costs versus the fixed team and overhead load.

Planning assumptions only; actual break-even can move with project mix, labor, and permit timing.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch plan	$263K	$76K	$312K	71%	-$125K	Still below break-even, so launch risk stays high.
Base first-year plan	$693K	$201K	$312K	71%	$180K	Clears break-even with a cushion, so small demand swings are less risky.
Full-capacity backlog plan	$1,460K	$409K	$392K	72%	$659K	Builds a wide cushion, but it depends on stronger backlog and more staff.

What breaks this break-even plan if sales slip or costs rise?

Stress test

The base case clears break-even, but the cushion shrinks fast if revenue slips or job costs creep up. Permit delays, freight spikes, subcontractor rate hikes, and change-order overruns are the main pressure points.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	Base case, no change.	$439K	$254K cushion	Plan clears break-even with room to spare.
Revenue shortfall	Revenue falls 15% to $589K.	$439K	$150K cushion	Still profitable, but the cushion drops fast.
Fixed-cost pressure	Add $5K in monthly overhead.	$509K	$184K cushion	Overhead growth cuts slack before sales move.
Margin pressure	Variable expenses rise from 29% to 34%.	$472K	$221K cushion	Freight and permitting costs can erase margin.
Combined pressure	Revenue falls 20%, variable expenses rise 5 points, and overhead adds $5K monthly.	$562K	$8K gap	Almost no cushion; one delay can push losses.

What should the founder verify before signing the lease and buying the vans for a dumbwaiter installation service?

Founder checklist

Yes—before you sign the lease or buy the fleet, confirm the model still works with $774K minimum cash by Month 2 and $145.5K in planned CapEx. The real test is whether early install demand, crew capacity, and fixed overhead still point to break-even by Month 6.

1Cash CushionMonth 2 / $774K

Confirm you can fund the minimum cash need through Month 2, because the launch can stall fast if the first equipment and hiring wave lands before collections.

2CapEx Load$145.5K

Verify the full spend for vans, hoisting gear, tools, storage, IT, safety gear, and the display model is covered before you commit, since these outlays hit early.

3Lead Flow$12K / $450 CAC

Check that the Year 1 marketing budget and customer acquisition cost still bring in enough qualified jobs before hiring beyond core staff, or payroll will outrun demand.

4Fixed Burn$7.5K fixed/mo

Make sure the non-wage fixed costs, including $4,200 rent and $1,100 liability insurance, still fit the break-even path and leave room for the work you actually sell.

5Margin Mix18% + 5% + 25%

Model unit economics with 18% for dumbwaiter units and components, 5% for raw materials, and 25% for permits and inspections, because margin slips show up fast in this trade.

6Backlog Gate5-9 installs/mo

Hold off on the second van until the backlog makes 5 to 9 monthly installs realistic, so added capacity raises revenue instead of sitting idle.