Use contribution, not the invoice total.
A $350 job does not leave $350 available for customer acquisition. First account for the direct costs of doing the work, such as labor, materials, job travel, and payment processing. What remains is the job’s contribution toward acquisition spending, other overhead, and profit.
The Small Business Administration’s break-even method divides fixed cost by price minus variable cost. This calculator applies that relationship to a defined monthly acquisition budget, not to all costs of operating your business.
Source: U.S. Small Business Administration: break-even analysis and its formula
Include a realistic cost for your own working time where it belongs. When a cost has already been included in direct job costs, do not add it again as a separate acquisition expense.
The calculation, step by step.
Contribution per jobCollected revenue − direct job cost
Jobs to cover acquisition spendMonthly acquisition spend ÷ contribution per job, rounded up
Inquiry planning targetWhole-job target ÷ inquiry-to-paid-job rate, rounded up
Effective cost per inquiryMonthly acquisition spend ÷ inquiries in the same period
The second step deliberately rounds up to completed whole jobs. The inquiry target is then based on that whole-job count and your chosen conversion assumption. It is a planning target, not the probability of reaching it.
The calculator also estimates contribution left after acquisition: inquiries × the assumed paid-job rate × contribution per job, minus acquisition spend. Expected job counts can be fractional in a scenario, even though actual completed jobs cannot.
Read the example without treating it as a forecast.
With $500 in monthly acquisition spending, $350 of collected revenue per job, and $225 of direct job cost, each completed job contributes $125. Four additional completed jobs would cover that $500 spending.
At an assumed 25% inquiry-to-paid-job rate, the planning target is 16 inquiries for those four jobs. With 20 inquiries at that same rate, the expected count is five paid jobs and $125 of contribution left after acquisition. That amount is not net business profit.
| Scenario assumption | Paid jobs from 20 inquiries | Contribution after $500 acquisition spend |
|---|---|---|
| 10% paid-job rate | 2 jobs | −$250 |
| 25% paid-job rate | 5 jobs | $125 |
| 40% paid-job rate | 8 jobs | $500 |
All three rows use invented inputs to demonstrate the arithmetic. They are not estimates of typical performance, promises of WebmPros results, or evidence that any property currently produces 20 inquiries a month.
Use comparable records.
Do not calculate your close rate from screened inquiries and then apply it to a count that includes every spam call. The numerator and denominator need consistent definitions.
For a practical review, keep the inquiry date, source, service fit, estimate status, and completed paid outcome together. Allow for the time between a request and the job. A monthly snapshot can undercount results when estimates have not yet been decided.
Do not count a repeat phone call and a matching form submission as two new opportunities without checking whether they concern the same project. See the qualified-inquiry guide for a way to organize the review.
Leave room for uncertainty.
The break-even acquisition ceiling per inquiry is contribution per job multiplied by the assumed paid-job rate. Spending that entire amount would leave nothing from those jobs for remaining overhead, tax, or a margin of safety. It is a ceiling in this simplified model, not a recommended bid or budget.
Test a lower close rate and a higher direct cost than you expect. Consider whether additional work would require another employee, more equipment, or a longer drive. Averages can hide those changes.
A zero booking rate or a job that costs at least as much to complete as it brings in does not support a positive acquisition budget in this model. The calculator will ask you to revisit those inputs rather than produce a misleading finite target.
Use the number to ask a better question.
Once you know the rough economics, compare them with the actual property’s inquiry history, service area, and commercial terms. A theoretical break-even point does not prove that enough suitable requests are available.
Review what belongs in a partnership quote, then discuss the relevant market preview. For a material financial decision, review your full costs with your accountant or financial adviser rather than treating a small calculator as a business forecast.