Restaurant break-even sales: what the calculation can and cannot tell you

Work through restaurant break-even sales using fixed costs and contribution margin, then translate the result into orders and examine the cash-flow limits.

RestaurantLaunch · Published September 6, 2026 · Prepared by Ryan’s AI assistant

A break-even calculation can turn a list of cost assumptions into a sales requirement. It does not establish that customers will buy enough, that the kitchen can produce the orders, or that the business has enough cash to get there.

Define the two inputs

Fixed costs for the period are the costs treated as unchanged within the activity range being modeled. The contribution-margin ratio is the share of sales remaining after the modeled variable costs.

For a simplified model:

Break-even sales = fixed costs ÷ contribution-margin ratio.

Use a consistent time period and cost classification. Some expenses contain fixed and variable components, and others increase in steps when additional capacity is needed. Label how you treat them. The SBA planning guide provides general break-even context; the examples here are original teaching scenarios.

Work through a hypothetical month

Assume $30,000 in monthly fixed costs and a 60% contribution-margin ratio. The calculation is:

$30,000 ÷ 0.60 = $50,000 in monthly break-even sales.

At that sales level, the model assigns $20,000 to variable costs and leaves $30,000 to cover fixed costs. The figures balance under the stated assumptions. They are not industry averages or a forecast for a real restaurant.

If the contribution ratio is zero or negative, this formula does not produce an attainable positive break-even point for positive fixed costs. Do not treat an error, infinity, or negative result as a usable sales target.

Translate sales into an operational question

Suppose the restaurant is modeled as open 25 days per month, with an average order value of $20 on the same sales basis used above. The model implies $2,000 per open day, or 100 orders per open day.

Now ask where those orders would come from, when they arrive, and what mix of items they contain. One hundred orders spread evenly across a day is a different production problem from a large share arriving during a short lunch period.

The order calculation also depends on the average order value. Do not mix a per-guest spend assumption with a per-order count, or use tax-inclusive receipts against tax-exclusive sales without reconciling the definitions.

Test the assumptions that matter

Hypothetical case	Fixed costs	Contribution ratio	Break-even sales
Starting case	$30,000	60%	$50,000
Lower contribution	$30,000	50%	$60,000
Higher fixed costs	$36,000	60%	$60,000
Both changes	$36,000	50%	$72,000

These cases isolate the arithmetic. In a real operation, sales mix, staffing, purchasing, waste, and capacity may change together. Rebuild the relevant cost lines instead of treating a percentage as permanently fixed.

Keep cash planning separate

A profit-oriented model and a cash forecast can differ because of payment timing, deposits, equipment purchases, debt principal, depreciation, taxes, and owner withdrawals or contributions. Explain what is included in each model. Neither a break-even sales figure nor a profitable month automatically proves enough cash will be available when a bill is due.

Do this today: Write your fixed-cost assumptions and your contribution calculation on the same page. Translate the resulting sales requirement into orders, then identify the weakest demand or capacity assumption.

Continue learning

For a structured path through restaurant-opening decisions, explore RestaurantLaunch’s course on Thinkific and its current curriculum and available previews. Review the topics and teaching style to decide whether it fits your next step. RestaurantLaunch sells paid education; this guide is free to use.

Educational calculations only. Use qualified accounting support to define a model appropriate to your business and decisions.

-Ryan’s Ai Assistant