Why Contractors Lose Money on Jobs: The Underbidding Math

You didn't lose money because the customer haggled. You lost it because you quoted from memory, and the memory was a year old. Here's the arithmetic, line by line.

The $500 job that paid you nothing

A furnace blower motor dies. The tech has done this job thirty times, so he quotes $500 without opening anything. That number formed in his head back when the motor cost $190. The customer says yes on the spot, which should have been the first warning.

Here's where the $500 actually went:

Now the hours. Not the wrench-time hours. All of them.

$191.20 divided by 5.0 hours is $38.24 an hour. That looks survivable until you remember it isn't pay. It's revenue. None of your overhead is in it yet: no truck payment, no liability insurance, no phone, no tool replacement. Charge that hour even a lean $25 overhead share and you took home $13.24 an hour. There are warehouse stores paying more than that to people who never crawl under a furnace, and they cover the vehicle.

Nothing about this job was unusual. The tech worked clean, the customer paid same-day. The only thing broken was the number, and it was broken before he rang the doorbell.

The costs contractors forget

Underbidding is rarely one big mistake. It's six small ones that always travel together:

• Drive time. Ninety minutes in the truck is ninety minutes you sold to this job. If it's not in the price, you donated it.
• Quoting and diagnosis time. The half hour you spent finding the problem and the time spent writing the quote happened whether or not you billed them. Win rate matters here too: if you close half your quotes, every won job carries the quoting time of a lost one.
• Callbacks and warranty returns. One free return visit a month, at the 5 real hours per visit we just counted, quietly erases the margin on a good job.
• Consumables and shop supplies. Tape, sealant, wire nuts, blades, gloves. $14 here looks like nothing. Across 300 jobs a year it's $4,200 of material you never invoiced.
• Payment processing. 2.9% plus 30 cents sounds like a rounding error until you notice it's $14.80 of pure margin on a $500 ticket, every ticket.
• Insurance per job-hour. Your liability policy doesn't bill you per job, but it should be priced per job, because that's how it gets paid.
• The second trip. The part you didn't have on the truck costs another 90 minutes of driving and another $12 of fuel, and the quote you already sent absorbs all of it.

None of these show up when you price a job in your head. All of them show up at the bank. That's the whole argument for applying real markup to real costs instead of a gut number to a guess.

Your break-even hourly rate

There is one number that ends underbidding, and most contractors have never calculated it:

Worked example. Say your overhead runs $47,600 a year: truck payment and commercial auto, liability insurance, health coverage, fuel, tool replacement, phone and software, license renewals, marketing, bookkeeping. For a one-truck operation that's lean, not padded. Say you want to pay yourself $70,000.

Why 1,200 and not 2,080? Because billable hours are not working hours. Fifty working weeks at 40 hours is 2,000 hours, and a real field schedule loses about 40% of them to driving, diagnosing, quoting, supply runs, callbacks, and paperwork. That leaves 1,200 hours anyone actually pays for. Divide by 2,000 and you'd get $58.80, a rate that feels safe and bankrupts you slowly.

Now hold the blower motor job against that number. It consumed 5.0 hours, so at break-even it needed to clear 5.0 × $98 = $490 after materials and fees. It cleared $191.20. That single "fine" job came in $298.80 short of break-even, and the tech left the driveway feeling good about it.

Price drift: how a profitable template goes stale

Templates are good. Stale templates are how profitable jobs rot in place. You priced the job carefully once, the math was right, and then you copied that quote for months while the underlying prices moved.

Say you built a water heater swap template in March: $589 for the unit, $94 for fittings, flex lines, and a pan. Materials, $683. You quote the job at $1,400, so everything above materials, $717, covers your labor, overhead, and profit. By June the same unit is $649 and the fittings basket is $103. Materials are now $752. You're still sending the March quote, so the job now throws off $648 instead of $717. That's $69 gone per job, and you never made a decision. Do that job twice a month and the drift costs you $138 a month, $1,656 a year, on one template. Most contractors are running ten.

The fix isn't re-pricing everything quarterly. It's pricing from live numbers instead of saved ones. FieldQuote pulls current prices from 16 suppliers, including Home Depot, Lowe's, Grainger, and Ferguson, so the material line in your quote is what the store charges today, not what it charged the day you built the template. The same drift hits every trade: it's why pricing HVAC jobs off last season's parts costs goes wrong, and why a plumbing estimate copied across a copper price move quietly loses money.

The 60-second profit check habit

You don't need a spreadsheet night every week. You need one habit: before any quote leaves your phone, run four checks.

• Current material cost. Today's price, not the price in your head and not the price in a three-month-old template.
• Real hours. Drive both ways, diagnosis, install, paperwork. The 5.0-hour job, not the 2.5-hour fantasy.
• Your markup. Applied on purpose, against your break-even rate, not vibes.
• The profit line. An actual dollar figure for what this job pays you after everything above.

That last one is the test of your whole setup. If you can't see the profit line before you hit send, you're not quoting. You're guessing, and the blower motor job is what guessing pays.

Job profitability FAQ