Guide
A step-by-step method for pricing your most common jobs off your own job history, not a national database, using one formula and a plain spreadsheet.
Most flat-rate books sold to trades are built from someone else's average job times, in a market that isn't yours, with a labour rate that isn't yours. They look professional. They are also wrong for your business the moment your travel times, your team's actual speed, or your local material costs differ from the average.
The fix is to build a small price book from your own invoices. You don't need 200 tasks. You need the 15-20 tasks that make up most of your repeat work, priced properly, with everything else left as time-and-materials until it earns its place in the book.
Every flat-rate task price is built from three parts:
Price = (measured task time × true hourly rate) + materials at marked-up cost + task-specific risk allowance
Go through your last 20-40 invoices (or job sheets, if invoices don't break out time) and pull out every job that repeats often: tap replacements, outlet swaps, filter changes, drain clears, whatever fits your trade. For each recurring task, record:
Then for each task type, list every measured time you've got and take the median, not the average. One 3-hour outlier job (blocked access, city inspector, whatever) will drag a small-sample average badly out of shape. The median resists that.
Example extraction for "kitchen tap replacement, like-for-like":
| Job | Time on tools |
|---|---|
| Invoice 114 | 0.6 hr |
| Invoice 129 | 0.75 hr |
| Invoice 141 | 0.5 hr |
| Invoice 158 | 0.65 hr |
| Invoice 172 | 1.8 hr (seized isolation valve) |
Average here is 0.86 hr, pulled up by one bad job. Median is 0.65 hr. Use 0.65 hr as your measured task time, and cover the seized-valve risk with the risk allowance instead of baking it into every job's base time.
If you've only got 3-4 data points for a task, keep collecting for another month before locking a price. Fewer than that and you're guessing, which defeats the point.
Take the 0.65 hr median time above.
Raw price: $61.75 + $72 + $15 = $148.75
Round to your banding rule (below): $150.
Compare that final number against a real job's actual cost and margin using the job profitability calculator before you commit it to the book. If the margin doesn't hold up once you account for every job in your sample, not just the fast ones, adjust the risk allowance or the base time.
Raw formula outputs look unprofessional and are hard for a customer to compare ("$148.75" invites questions). Apply two rules:
Banding also hides small errors in your time data. If two tasks are genuinely close, treat them as one line rather than chasing precision you don't have the sample size to support.
Don't try to flat-rate everything. Pull a year of invoices, tag each job by task type, and count frequency. In most small trade businesses, a fairly small set of task types covers roughly 80% of job volume — repeat callouts, standard installs, common repairs. That's your price book. Everything else — the one-off, the unusual, the "never seen this before" job — stays time-and-materials.
Trying to flat-rate rare work is where price books go wrong. You end up guessing a time for a task you've done twice, pricing it badly, and either losing money or scaring off the customer with an inflated price built on a fake risk allowance.
A price book is not a one-off project. Costs move, techs get faster or slower, suppliers change prices. Set one clear rule: if a task's actual time on the last 5-10 jobs drifts more than 15% from the booked time, pull it and re-cost it.
Example: your tap replacement is booked at 0.65 hr. If your last eight of these average 0.80 hr or more, that's a 23% drift — over the threshold. Re-run the extraction, find out why (new fitting style, different supplier, slower access on recent jobs), and reprice.
Check this monthly, not annually. A stale price book quietly bleeds margin for months before anyone notices the pattern in the invoices.
One row per task, columns for: task name, sample size, median time, hourly rate, labour cost, material cost, markup %, risk allowance, raw price, rounded price, band group, date last re-costed, and drift %. That's it — no software needed. If you want a template built around this exact structure alongside your rate and job-costing tools, the small business operations kit bundles the price book, hourly rate, and profitability sheets together so they stay consistent with each other.
Twenty tasks, priced from your own numbers, reviewed monthly, will out-earn a 300-line national price book every time. It's smaller, it's honest about what you actually know, and it gets more accurate every month you run it.
The Small Business Operations Kit ($19) turns guides like this one into fill-in-once worksheets: rate card, quoting sheet, job costing, payment terms and follow-up templates. Built by the same people who write these guides.