Two jobs can bring in the same revenue and cost very different amounts to complete. One truck travels six miles and is back in service quickly. Another travels farther empty, waits at a locked gate, and returns across town. Counting only loaded miles hides much of the difference.
Build a worksheet from your own records before you use an industry rule of thumb. The U.S. Small Business Administration’s break-even calculator provides the basic fixed-cost and contribution approach. The numbers below are fictional. They are not market rates, a quote to customers, or a replacement for contract terms, local rules, or advice from your accountant.
Define the jobs you want to compare.
Start with a narrow group, such as routine light-duty private calls in a familiar service area. Keep recovery, storage, longer transport, and contract work in separate groups when their costs and receipts differ. The purpose is to learn what a typical job in that group uses, not to average unlike jobs into a single price.
Use completed jobs from the same period as the expenses you are comparing. Record cancelled calls or trips that did not result in a tow separately. They still consume time and fuel, and their treatment depends on whether the account actually paid anything for the trip.
Measure the whole trip, including the empty miles.
Record mileage from assignment or departure through the point the truck is available again, using a consistent definition. Capture operator time the same way. Keep an eye on waiting time, trip-related tolls, payment processing, and consumables when they apply. A job is still tying up the truck while it waits for a gate to open.
Put expenses that vary with a job in one column, and recurring overhead in another. A portion of labor or maintenance may behave differently depending on your setup. Choose a treatment with your accountant when needed and use it consistently. If you include a maintenance reserve in per-mile costs, avoid counting the same reserve again in fixed overhead.
Separate billed amounts from money retained.
Start with the amount actually expected for the work after approved discounts, credits and write-offs. Separate taxes or pass-through charges as appropriate for your books. If a payment fee is already included as a direct cost, do not subtract it twice. When invoicing and payment fall in different periods, ask your bookkeeper how to reconcile the timing rather than mixing inconsistent cash and accrual figures.
A dispatch record and an invoice should share a job ID. That lets you spot whether the invoice reflects the job that was actually performed. It also makes it easier to identify whether a margin problem comes from job costs, invoice corrections, or slow collections.
Work through the math with round numbers.
Assume a business receives $110 per completed job and averages $55 in job-dependent costs. Each job leaves $55 toward monthly overhead. With $4,400 in fixed monthly costs, dividing by $55 gives 80 completed jobs to break even under these assumptions. At 80 jobs, the average fixed share is $55 per job, so the estimated full cost is $110.
If the same business completes 60 jobs, the fixed share rises to about $73.33 per job, and the estimated full cost is $128.33. The work did not necessarily become more expensive per mile; fewer jobs shared the fixed cost. If the $55 variable cost rises to $65 instead, contribution drops to $45 and the break-even volume becomes 98 jobs after rounding up. These examples assume the same price, cost and job mix throughout the month.
A simple break-even example
| Worksheet input | Illustrative value | How to fill in your own |
|---|---|---|
| Monthly fixed overhead | $4,400 | Add recurring costs for the period; avoid duplicating reserves |
| Average net job revenue | $110 | Use consistent figures from completed jobs |
| Average variable job cost | $55 | Include job time, trip miles and applicable direct costs |
| Contribution per job | $55 | Subtract variable cost from net revenue |
| Break-even completed jobs | 80 per month | Divide fixed overhead by contribution and round up |
Test assumptions before making a decision.
Ask what happens if one truck is unavailable for a week, an account adds an approval step that causes delays, or fuel prices change. Run a low, expected and high volume case. Keep the assumptions on the sheet so another person can tell which inputs changed. If actual jobs routinely take longer than planned, look at the delays before simply raising the volume forecast.
The worksheet tells you which question to investigate next. If empty miles dominate, look at geography and dispatch coverage. If jobs wait on approvals, review the account’s handoff. If overhead is hard to explain, check that recurring bills and reserves are being assigned once and to the right period.
Make it a 15-minute monthly review.
Pick a few representative job records and reconcile the dispatch time, miles, invoice and expected receipts. Compare the new month with a month that has a similar service mix. Note what changed and whether it happened once or kept recurring. Keep the sheet internal; the goal is to know your own cost base so you can make decisions with better evidence.
If the monthly capacity case depends on a backup truck, use the downtime coverage plan to check whether that coverage is real. A spreadsheet does not make a truck or an operator available.
Common questions
What if contribution per job is zero or negative?
Under those assumptions, more jobs at the same revenue and cost will not cover fixed overhead. Check your inputs and review the economics of that job group.
Should storage revenue be included?
Track it separately if it has a different cost pattern or collection timing. Use an approach consistent with your books and the actual terms of the work.
Is this the amount I should charge?
It is an internal cost estimate. Permitted charges, contracts, discounts, taxes and customer quotes are separate decisions.