Job-costing basics so you stop guessing at quotes

A quote that came out of your head can be right. It can also be a number you said because it felt close to last month's job, or because you were standing in a driveway and wanted the conversation to end. If you run a small shop, a few of those guesses will be fine. A few will be the week you worked hard and somehow did not get paid for the time you actually spent.

This is a simple worksheet, not an accounting course and not a software review. You can fill it in on paper. You should label every rule of thumb as a rule of thumb, not as a law, and you should never paste a "typical margin in this industry" figure that you cannot source from your own books. We will not invent one for you.

What belongs on the page

For each job you are about to quote, write:

1. Labor hours you really expect, including the time to talk, to clean up, and to write the invoice later if that is you
2. Labor cost, using the burdened number you actually pay (wage plus the extras you already know: payroll taxes, insurance you can allocate, and so on). If you do not have a precise burdened rate yet, use a working rate and write "working rate" next to it.
3. Materials and supplies, plus tax and a small waste or leftover factor you can defend
4. Drive time and vehicle cost for this job, not "travel is just part of the day" unless you have already put that time somewhere else
5. A callback or warranty risk line, even if the number is small
6. Overhead you want this job to carry (rent, software, unpaid office hours)
7. The profit you want after that, as a number, not a hope
8. The quote you will actually say

If you cannot fill a line, write "unknown" and decide whether you can still quote, or whether you need to see the job first. Guessing quietly is worse than saying "I need to look, then I'll give you a number."

A fill-in worksheet

You can copy this onto a pad or a sheet you already use.

• Job / customer: ________
• What we think the work is: ________
• Labor hours (include setup, cleanup, invoicing if the tech or owner does it): ________
• Burdened or working labor rate: $________ (label which)
• Labor subtotal: $________
• Materials and supplies: $________
• Waste / freight / small parts: $________
• Drive time (hours) and vehicle cost: ________ / $________
• Callback or warranty reserve: $________ (rule of thumb: ________, or a dollar amount you chose)
• Overhead share for this job: $________
• Subtotal before profit: $________
• Profit you want: $________
• Quote: $________
• What you will say if the scope changes: ________

Example only, not a market average and not a recommendation for your trade: a half-day repair, 4 labor hours at a working rate of $75, $180 in parts, 45 minutes of drive time you cost at $40, a $50 callback reserve, and $60 of overhead is a different quote than "I usually charge about $500 for this." Do the arithmetic on your own numbers. If your rates are different, the example is only there to show the rows.

Labor is where guesses hide

Owners often under-count the time that is not "turning wrenches": the parts run, the second trip, the customer conversation, the invoice, the callback that ate Thursday evening. If you are a one-person shop, that time is still your time. Put it on the page.

A rule of thumb some shops use, and it is only a rule of thumb, is to look back at three similar jobs and use the median hours, not the best one you remember. If you do not have three similar jobs, say you are estimating, and add a clear change-order sentence to the quote.

Do not use a national "hours for this repair" chart unless you trust it and you have checked it against your own work. Your attic stairs are not the chart's attic stairs.

Drive time and callbacks

Drive time is easy to treat as invisible, especially when you are already out. It is not invisible in the day. If a job is thirty minutes across town, that is an hour of round trip you cannot sell to someone else, plus fuel and wear. You can put travel into the labor hours, or you can give it its own line. Pick one method and use it consistently so you do not double-count or forget it.

Callbacks are the other quiet cost. You will not predict them perfectly. You can still put a small reserve on jobs that often need a return visit, and you can write "none added" on a job where you are not going to. A reserve you chose is honest. A made-up percentage from a blog is not. If a callback happens, look at it the next week when you review invoices and collections, and when you look at scheduling buffers. A job that always overruns should change the next quote, not just your mood.

How to talk about the number

You do not have to show the customer the whole worksheet. You do have to be able to stand behind the quote. If they ask why, you can talk in plain language: the time, the parts, the second trip if we need it, the fact that the price holds for the scope you wrote down.

Write the scope in the quote. "Replace the failed valve and check for leaks in the immediate area" is a scope. "Fix the plumbing" is an argument waiting to happen. When the scope changes, you already wrote what you would do: stop, re-quote, or use a written change.

If you are standing in a driveway and cannot run the numbers cleanly, it is allowed to say, "I can do a service diagnostic today for $X, and I'll give you a written number for the repair before we start." That is not weakness. That is how a small shop avoids a guess it will regret.

What we would do in a 1–20 person shop

We would print the worksheet this week and use it on the next five quotes, even if we already "know" the number. We would compare the quote to the actual hours and parts after those jobs close, and we would adjust the working rate or the callback reserve based on our own results. We would not install a new costing platform to begin, and we would not borrow someone else's margin figure.

If two of the five jobs were badly off, we would look at the hidden time first (drive, parts run, talk, invoice) before we assumed we should just charge "more." The point is not a perfect cost system. The point is to stop guessing in the dark, and to have a page you can hand a first office person later so the quote does not live only in the owner's head.

This article was drafted with AI assistance and reviewed by AuraGrid Labs editorial. Front of Shop is published by AuraGrid Labs LLC.