Use the calculator above to estimate the sales and guests needed to cover your restaurant's monthly operating costs. Enter fixed costs, average spend per guest, variable cost per guest and the number of days you open.
The worked example uses USD. The calculator works with EUR, GBP, AUD or another currency as long as all three money inputs use the same one. No account is required.
The restaurant break-even formula
Contribution per guest = Average spend − Variable cost per guest
Monthly break-even guests = Fixed costs ÷ Contribution per guest
Contribution margin ratio = Contribution per guest ÷ Average spend
Monthly break-even sales = Fixed costs ÷ Contribution margin ratio
Daily guest target = Monthly break-even guests ÷ Days open
The calculator rounds guest targets up to whole people. It calculates the daily sales average from unrounded figures, so multiplying the rounded daily guest target by average spend will usually produce a slightly higher amount.
This is the standard contribution-margin approach also used in the U.S. Small Business Administration's break-even calculator. For a restaurant, using average spend per guest represents your mix of menu items rather than a single product.
What to include in fixed and variable costs
The useful distinction is how a cost behaves over the sales range you are planning for. An expense paid hourly does not automatically vary with every additional guest.
| Cost | Treatment to consider |
|---|---|
| Rent, insurance and software subscriptions | Usually fixed within the month |
| Salaried management and baseline staffing | Fixed for the operating plan you are testing |
| Ingredients, packaging and transaction fees | Variable to the extent they increase with sales |
| Extra service hours | Variable only if they change with guest volume in your plan |
| Utilities | Split standing costs from the portion that changes with activity where practical |
Put each cost in one place. If baseline kitchen wages are in monthly fixed costs, do not include those wages again in variable cost per guest. A busier service may require an extra person for a whole shift; that step change means you should rerun the calculation with the revised staffing plan.
Keep operating break-even separate from cash planning. Loan principal repayments and equipment purchases affect cash needs but are not operating expenses in the same way as rent. Plan those cash outflows separately rather than interpreting this result as the bank balance you need. Include the operating costs relevant to your records consistently.
A worked example
This is a fictional planning example, not an industry benchmark or a customer result.
| Input | Amount |
|---|---|
| Monthly fixed operating costs | $19,000 |
| Average net spend per guest | $22 |
| Variable cost per guest | $12 |
| Days open | 26 |
Each guest contributes $22 − $12 = $10 toward fixed costs. The contribution margin ratio is $10 ÷ $22 = 45.45%.
At that margin, monthly break-even is 1,900 guests, or $41,800 in net sales. Dividing 1,900 by 26 gives about 73.08 guests per open day. The calculator therefore displays a daily target of 74 guests. Rounding down to 73 would fall short if every day had exactly that count.
The unrounded daily sales average is $1,607.69. Seventy-four guests spending $22 each produce $1,628, slightly more than that average because you cannot serve a fraction of a guest.
Real trading days differ. You could serve fewer guests on a Tuesday and more on a Saturday while still reaching 1,900 for the month. Use the daily figure as a planning average, then compare the monthly total too.
How to find your own inputs
Use a consistent reporting period. Take a recent complete month and check whether it reflects the month you are planning. A holiday closure or one-off event can distort the average.
Calculate net spend per guest. Divide net sales by guests served. Exclude sales tax/VAT and tips from the sales figure used here. If your operation counts orders rather than guests, you can model orders instead, but both the spend and variable cost inputs must then be per order. Interpret the displayed guest targets as order targets.
Estimate the variable portion carefully. Include the costs that rise with those sales. The food cost guide explains how beginning stock, purchases and ending stock determine ingredient consumption. Divide matching variable costs by the matching number of guests.
Use actual open days. Enter 26 for a month with 26 trading days, rather than dividing by 30 automatically. Recheck assumptions after a menu-price change, supplier-price change or new staffing pattern.
What if the target looks impossible?
Compare required guests with seats, table turns, opening hours and kitchen capacity. A mathematical break-even point above practical capacity is a reason to revisit the plan, not a promise that more demand will solve it.
In the example, a $2,000 increase in fixed costs adds 200 guests per month at a $10 contribution. If variable cost rises from $12 to $13 while average spend stays $22, the contribution falls to $9 and the monthly guest target rises to 2,112, rounded up.
Try changes one at a time so you can see what moves the result. Cost reductions, menu changes and service capacity affect each other; the calculator assumes average spending and variable cost stay constant within each scenario.
Turn the target into a regular check
Use the free daily sales report to record net sales and guests, then compare the month-to-date pattern with your plan. Keep notes on unusual services so a strong event night does not hide a weaker recurring trend.
TableAI can help you record daily sales and stock updates through WhatsApp and receive a morning briefing. This public calculator is separate from your account and does not read restaurant records or save a target in TableAI. See how the daily workflow works.
Common questions
What happens if variable cost equals average spend?
There is no positive contribution toward fixed costs. The calculator asks you to revise the inputs rather than showing a finite break-even target. Check for double-counted costs or an unviable sales margin.
Why is prime cost different from variable cost?
Prime cost combines food and labor costs. Labor includes baseline staffing that may remain fixed for a service. For break-even, split costs by how they behave instead of treating the entire prime-cost percentage as variable.
Does reaching break-even mean I can withdraw the remaining cash?
No. This estimates coverage of the operating costs entered. Debt repayments, equipment spending, tax payments and working-capital timing can affect available cash separately.
Are the amounts sent anywhere?
The calculation runs in your browser. The tool does not send its input amounts to TableAI or require a signup.