Capacity is the number the office should check before it decides anything about marketing, hiring or overtime. If next Tuesday is half empty, it's time to call members due for a tune-up. If the next two weeks are full in July, more ad spend only creates customers you can't serve.
Capacity in plain English
Picture an example eight-tech HVAC shop. Each tech is scheduled 40 hours a week, so the shop has 320 paid hours. One tech is on vacation (minus 40), the Monday safety meeting takes an hour from each of the other seven (minus 7), and parts runs and truck restock take about two hours per tech (minus 14). That leaves 259 hours of time techs can actually be on jobs.
Those 259 hours are your capacity for the week. Every booked appointment uses some of it, and every hour left is a slot the office can still sell.
How do you calculate capacity?
- 1
Start with scheduled hours
Each technician's shift hours for the period. For reference, production workers at specialty trade contractors averaged about 39.5 paid hours a week in August 2026 (BLS, preliminary).
- 2
Take out time that isn't on jobs
Time off, holidays, meetings, training, shop and restock time. What's left is available hours.
- 3
Decide how to handle drive time
Either subtract an expected drive allowance to get sellable hours, or keep it in and add a drive buffer between jobs when booking. Do one, not both.
- 4
Compare with booked hours
Sum the expected duration of every appointment in the period. Booked ÷ available is capacity used.
The average weekly hours figure above comes from the BLS Current Employment Statistics survey.1 It is a useful sanity check on how many hours your techs are actually paid, not a target.
A worked example
| Example week | Hours |
|---|---|
| Scheduled hours (8 techs × 40) | 320 |
| Vacation (1 tech) | −40 |
| Meetings, training, shop and restock | −21 |
| Available hours | 259 |
| Booked appointment hours | 220 |
| Capacity used | 85% |
Capacity used
Common mistakes
- Using paid hours as capacity. Paid hours include meetings and shop time no customer can book.
- Booking with default durations nobody checks. If a job type's default is 60 minutes and it usually takes 100, the board looks emptier than it is.
- Counting overtime as standing capacity. Federal law requires time-and-a-half for hours over 40 in a workweek for covered employees,2 and some states add daily rules. Overtime is a surge tool, not a plan.
What is a good capacity target?
There is no published industry standard. What queueing math does show is why 100% is the wrong goal. Little's law ties the average amount of work in a system to the arrival rate and the time each job spends in it.3 Kingman's heavy-traffic result shows that waiting grows roughly in proportion to u ÷ (1 − u), where u is how full the system is.4
Computed from Kingman's formula term. Relative values only: at 90% full, expected waiting is about nine times the 50% level.
| 50% full | 1 |
|---|---|
| 70% full | 2.3 |
| 80% full | 4 |
| 85% full | 5.7 |
| 90% full | 9 |
| 95% full | 19 |
Source: Kingman (1961), computed
In practice, that means a board booked to the last minute days ahead has no room for no-heat calls or a job that runs long, and the afternoon arrival windows slip first. Pick a target with slack (many shops choose somewhere in the 80s) and adjust it by season. Why your 2 p.m. arrival window keeps slipping runs a full simulation of this effect.
What moves capacity
| Lever | Why it works | How to check |
|---|---|---|
| Accurate job durations | Bookings match how long work really takes | Booked vs actual time by job type |
| Less drive time | More of each day goes to jobs | Drive minutes per job, by zone |
| Higher first-time fix | Fewer return trips eat slots | Return trips per 100 jobs |
| Shoulder-season maintenance | Moves planned work out of peak weeks | Booked hours by week, 4 weeks out |
| Hiring or apprentices | Adds hours, slowly | Weeks above target for a month or more |
Capacity and utilization are linked but not the same: one is about the schedule, the other about the tech's paid week.
How do you plan capacity for peak season?
Demand in heating and cooling work bunches into a few weeks of extreme weather, while capacity stays almost fixed. You can't hire your way through a heat wave, so the planning happens months earlier:
- Book planned work into the shoulder seasons. Maintenance visits done in April and October free summer and winter hours for breakdowns.
- Hold back emergency slots. Leave a set number of hours open each day in peak weeks and release them to normal bookings by early afternoon if no emergencies come in.
- Cross-train for the common calls. A plumber who can handle a basic no-cool diagnostic adds peak capacity without a new hire.
- Decide your overtime limit in advance. Know how many extra hours you'll pay for, and for how many weeks, before the first hot week arrives.
How capacity shows up in TradesWork
In TradesWork, one capacity engine reads each tech's shift, time off, meetings, existing appointments, required skills and a drive buffer between jobs. The same engine feeds the dispatch board, online booking, the AI receptionist and the text agent, so nobody can offer a window the team can't cover.
Ask the business adds a four-week demand vs capacity forecast: booked hours plus typical late bookings, adjusted for the season, against a capacity goal of 85% by default. Weeks at least 8 hours short of goal are flagged thin, while there's still time to fill them.
Footnotes
-
Average weekly hours of production and nonsupervisory employees, specialty trade contractors (CES2023800007), U.S. Bureau of Labor Statistics. 39.5 hours in August 2026 (preliminary), seasonally adjusted. ↩
-
29 U.S.C. 207, Maximum hours, United States Code, via Cornell Legal Information Institute. ↩
-
A Proof for the Queuing Formula: L = λW, John D. C. Little, Operations Research 9(3):383–387, 1961. ↩
-
The single server queue in heavy traffic, J. F. C. Kingman, Mathematical Proceedings of the Cambridge Philosophical Society 57(4):902–904, 1961. ↩
