Most under-pricing is not a judgement error. It is arithmetic, or it is hours nobody counted.
Start from the margin, not the cost
Decide the margin the business needs, then work backwards to the price.
To hit a 40% margin on a part costing $100: divide by one minus the margin. $100 ÷ 0.60 = $167.
Do not add 40% to the cost. That gives $140, which is a 29% margin, and it is wrong on every job forever. See markup and margin.
Count every hour the job consumes
The hours that get missed are the ones not spent working:
Travel, both ways. Paid labour that appears on no invoice. Loading and unloading. The quote itself, and any site visit to produce it. Picking up materials. Paperwork and invoicing.
A "two hour job" is routinely four hours of paid time. Pricing it as two prices it at half.
Cover overhead, not just cost
Your hourly rate has to carry a share of rent, insurance, vehicles, admin and your own pay — not just the technician's wage.
Break-even divided by your available billable hours is the floor. Anything below it loses money no matter how busy you are.
Then adjust for the specifics
Difficulty and access. A tight loft, a third floor, no parking. Urgency. Same-day is worth more and should cost more. Risk. Old systems, unknown conditions, work you cannot see until you open it. Distance. See service zones — drive time is the cost that never appears on an invoice.
Give options rather than one number
Good, better, best changes the question from "yes or no" to "which one", and reliably raises both the win rate and the average value.
Check whether it worked
The quote is a prediction. Job margin is the outcome, and the gap between them is the most useful number in the business. It only exists if both halves are recorded — see job costs.
If a job type is consistently below its quoted margin, the price is wrong, not the crew.