Performance Auto Parts Shop Break-Even: About $33K/Month

Fixed costs $27.0K/mo Base monthly overhead

Contribution margin 81% After variable costs

Break-even revenue $33.3K/mo Revenue target

Break-even timing Month 25 Model break-even

Break-even calculator

Use this calculator to test monthly revenue, variable expenses, and fixed costs against break-even for a performance auto parts shop.

Lean Base Full

Monthly revenue Sales drive the margin available to cover fixed costs. $ Lower sales Higher sales Variable expenses Wholesale inventory and shipping rise with sales. $ Lower cost Higher cost

Money available to cover fixed costs $91,577 $110,333 revenue - $18,757 variable expenses

Margin ratio

83%

Covers fixed costs

Yes

Fixed monthly costs Rent, payroll, software, and overhead must be covered each month. $ Lower cost Higher cost

Break-even chart Revenue Total costs

Which expenses are fixed and which move with sales in a performance auto parts shop?

Cost classification

Break-even gets reliable only when sales-linked costs are pulled out before contribution margin. In this model, Month 25 break-even depends on treating inventory, freight, payroll steps, and overhead differently.

Expense	Cost	Break-Even Treatment	Common Mistake
Retail Showroom Rent, $6,500/month	Fixed	Include in monthly overhead across the planning range.	Tying rent to sales volume.
Wholesale Inventory Cost, 12% of revenue in the first year	Variable	Subtract from revenue before calculating contribution margin.	Treating inventory purchases as fixed overhead.
Shipping and Logistics, 7% of revenue in the first year	Variable	Include freight gaps with other sales-linked costs.	Burying freight inside rent or payroll.
Salaried Store Roles, $167,500/year in the first year	Semi-fixed	Convert to about $13,958/month, then step up as headcount rises.	Ignoring payroll creep as visitors grow.
Utilities and High-Speed Internet, $850/month	Semi-variable	Use the base monthly charge, then add usage if hours expand.	Treating every utility dollar as fixed.
Marketing and Community Events, $3,000/month	Semi-fixed	Include planned spend and step it up when event cadence grows.	Cutting it from break-even because it feels optional.
POS and Inventory Software Subscription, $450/month	Fixed	Include as overhead while the subscription stays unchanged.	Allocating the subscription per order.
Liability and Inventory Insurance, $1,200/month	Semi-fixed	Carry the monthly premium, then reset when coverage tiers change.	Leaving out increases as inventory value grows.

How does break-even change from a lean launch store to a full mature store?

Scenario table

The lean case is still below break-even, the base case is almost there, and the full case has a wide cushion. Higher traffic and a better product mix lift revenue faster than fixed payroll grows.

Planning cases only. Actual results will vary with traffic, mix, pricing, and staffing.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch store	$19.5k	$3.7k	$27.0k	81%	-$11.2k	Needs about $13.8k more sales to break even.
Base year-2 store	$47.3k	$8.5k	$38.0k	82%	$0.7k	Revenue is just above break-even, so the cushion is thin.
Full mature store	$471.8k	$70.8k	$44.9k	85%	$356.1k	Revenue sits far above break-even, so the cushion is wide.

What breaks the break-even plan for a performance auto parts shop?

Stress test

Year 2 is close to break-even, with only about a $10k monthly cushion on $473k sales. A small sales dip or a few points of margin loss turns that into a loss fast.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$463k	$10k cushion	Thin cushion, so a small miss flips profit.
Revenue shortfall	Monthly sales fall 10% to about $425k.	$463k	$31k gap	A modest demand drop turns the month negative.
Fixed-cost pressure	Monthly fixed costs rise 10% to about $418k.	$510k	$30k gap	Rent or payroll creep eats the cushion fast.
Margin pressure	Variable expenses rise from 18% to 23% of sales.	$494k	$21k gap	Freight spikes and returns push break-even higher.
Combined pressure	Sales fall 10%, fixed costs rise 10%, and variable expenses rise to 23%.	$543k	$91k gap	All three hits put the shop deep in the red.

Can this performance auto parts shop cover the lease before you sign the space?

Founder checklist

Yes, but only if the site, traffic, and stock plan support the model. The hard check is whether the shop can carry $6.5K rent, about $14.0K monthly Year 1 payroll, and a $391K cash need before Month 24.

1Lease load$6.5K/mo

Verify parking, access, and the local car crowd can support $6.5K rent, because the lease becomes the anchor cost once you open.

2Visitor conversion8.0%

Test whether the 15-to-40 daily visitor forecast can convert at the Year 1 rate of 8.0%, since break-even needs buyers, not just traffic.

3Opening stock$120K

Keep the first buy near the $120K initial inventory plan so you cover the core kits, modules, brakes, intakes, and apparel without bloating dead stock.

4Supplier terms12.0% COGS

Lock supplier pricing before you assume the 12.0% wholesale inventory cost, because a few points of cost creep can push Month 25 break-even out.

5Payroll ramp$14.0K/mo

Hold Year 1 payroll near $14.0K a month and delay extra hires until sales prove the lift, or fixed cost will outrun demand.

6Cash runway$391K

Protect at least the $391K minimum cash cushion through Month 24, then watch Month 25 break-even and Month 39 payback to see if the store is really scaling.