Auto Parts Manufacturing Break-Even Revenue: About $149K/Month

Fixed costs $123.3K/mo Year 1 base

Contribution margin 82.5% After variable costs

Break-even revenue $149.3K/mo Monthly target

Break-even timing Month 1 Launch month

Break-even calculator

Test whether monthly revenue covers variable expenses and fixed monthly costs, then see if the operation clears break-even.

Lean Base Full

Monthly revenue Monthly sales set the margin pool that covers fixed overhead. $ Lower sales Higher sales Variable expenses Use direct materials, commissions, and shipping that rise with sales. $ Lean costs Higher costs

Money available to cover fixed costs $614,023 $724,167 revenue - $110,144 variable expenses

Margin ratio

85%

Covers fixed costs

Yes

Fixed monthly costs These are the monthly costs the business must cover before profit. $ Lean overhead Heavier overhead

Break-even chart Revenue Total costs

Which auto parts manufacturing expenses are fixed, and which move with sales?

Cost classification

Break-even is only reliable when rent, staffing, and unit-level charges sit in the right buckets. Misclassifying one large line can make Month 1 break-even look safer than it is.

Expense	Cost	Break-Even Treatment	Common Mistake
Factory Rent	Fixed	Use $25,000 per month as baseline overhead from Month 1 through Month 60.	Spreading leasehold improvements into monthly break-even instead of excluding capex.
Factory Utilities	Semi-variable	Use the $8,000 monthly base plus product utility percentages tied to revenue.	Treating all utilities as fixed and missing usage tied to production volume.
Sales Commissions	Variable	Apply 5.0% of first-year revenue, stepping down by model year as shown.	Modeling commissions as payroll and overstating fixed monthly burn.
Shipping & Logistics	Variable	Apply 4.0% of first-year revenue, then reduce by year per the forecast.	Leaving freight below gross margin and overstating contribution per unit.
Component Handling, Inspection, Tooling Wear, Consumables, and Rework	Variable	Apply the per-unit charges by product line before calculating contribution margin.	Averaging all product lines and hiding heavier unit charges on complex assemblies.
CEO, Managers, Engineering, Supervision, and Quality Roles	Fixed	Use $81,250 per month in first-year wages unless roles are tied to production shifts.	Making all salaries variable just because unit volume rises.
Direct Materials	Variable	Add supplier quotes per unit before launch; the model does not provide separate direct material inputs.	Assuming missing material quotes are zero and overstating break-even safety.

How does break-even change from a lean mix to base and full production?

Scenario table

Break-even gets safer as volume rises because fixed plant and payroll costs are spread over more output, while variable costs rise more slowly than revenue. The Year 1 mix sits right on break-even; Year 5 gives the widest cushion.

Planning figures use model assumptions and can move with product mix, scrap, and staffing.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean break-even mix	$149K	$26K	$123K	82.5%	$0	At this mix, one small miss can flip profit to loss.
Base Year 1 mix	$455K	$80K	$123K	82.5%	$252K	Year 1 clears break-even with a solid monthly cushion.
Full Year 5 mix	$917K	$119K	$169K	87.0%	$628K	Higher output spreads overhead and cuts break-even risk.

What breaks first if demand slips or costs climb?

Stress test

Year 1 has a $3,056K cushion over the $1,494K break-even line, so the plan clears break-even. The weak spot is cash: Month 7 still dips to negative $301K if sales lag, rework rises, or supplier quotes move up.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$1,494K	$3,056K cushion	Strong opening cushion, but Month 7 cash still turns negative.
Revenue shortfall	Year 1 revenue misses plan by the full $3,056K cushion.	$1,494K	$0 cushion	Any further miss pushes the plan below break-even.
Fixed cost up	Fixed costs move to the Year 5 run rate.	$1,691K	$2,859K cushion	Higher staffing and underused machines raise the floor.
Margin squeeze	Supplier quotes and rework push break-even to $1,943K/month.	$1,943K	$2,607K cushion	Small input shocks can eat the margin fast.
Combined stress	Year 5 fixed costs and margin pressure hit together.	$2,664K	$1,886K cushion	This is the danger zone for quotes, rework, and idle capacity.

What should you verify before committing to the plant lease and machine buy?

Founder checklist

Do not sign the lease, buy machines, or hire the plant team until demand covers about $1.494M a month in break-even revenue and the first-year plan of $455K a month looks real. The Month 7 cash dip to -$301K means the build has to survive the gap.

1Demand base$1.494M/mo

Confirm real orders can reach the break-even line before you commit to the plant.

2Launch plan$455K/mo

Check that the Year 1 mix can hit this monthly run rate, because it is only about 30% of break-even.

3Fixed load$124.5K/mo

Verify you can carry rent, utilities, insurance, software, legal, security, office spend, and payroll from Month 1.

4Margin floor82.5% pre-material

Treat this as a floor only and lock supplier quotes first, because the model does not split out direct materials.

5Line output250,000 units

Confirm the line, quality checks, and staffing can move the Year 1 unit plan without rework delays.

6Cash floor-$301K

Fund the Month 7 low point and the $3.4M capital spend (capex) buildout, or launch cash will run too tight.