Five formulas for modeling garage door service jobs

What to take away

Garage door service jobs can be modeled through five formulas: hourly recovery, consumed time, parts recovery, callback allowance, and a final market check. Each depends on the shop's own records.

Move one: what an hour on the road has to recover

Define, for a period you can measure:

Use the same period and cost allocation throughout: P is payroll cost assigned to service work; V is service-vehicle operating cost; S is shop and other operating overhead assigned to service work; H is the number of service hours recorded for that period that the shop uses to recover those costs. Divide the allocated costs by those hours, avoid counting a cost in more than one bucket, and exclude hours unrelated to service.

The recovery rate is (P + V + S) divided by H. That figure is what an hour has to earn before the business has made anything.

Calculate it from your own records. The published wage tables for occupations and areas are useful only as a check on whether the pay assumption inside P looks plausible where you work.

H is where people flatter themselves. Use hours you can evidence from job records, not from a working week multiplied by a number of technicians.

Move two: the hours this job will actually take

For the specific job, estimate:

T is time spent on the job, D is travel time attributable to it, including the round trip, and A is job-related administration such as dispatch, documentation, and customer follow-up. Record each in hours and allocate shared time consistently. Their sum is time the visit consumes for pricing purposes, not necessarily a separate line item on the customer’s invoice.

Billable hours for pricing purposes is T + D + A. The instinct to price only T is what makes distant jobs quietly unprofitable, and it is why two identical repairs at different ends of a service area are not the same job.

Move three: parts, at what they cost you to carry

Parts recovery is C plus W plus G, and it is compensation for carrying and warranting the part rather than a profit center. Whether you carried the right part at all is a stock question, worked through in the equipment and setup guide.

To calculate W, total the recorded cost of stock that sat, was damaged, or was opened but unused, then allocate it across matching parts issued; use categories when different parts have different loss patterns. To calculate G, total documented warranty replacement and handling costs for comparable parts and allocate them across those parts issued. Keep the periods and categories consistent, and do not count a callback cost here if it is already included in F × R.

Move four: the callback allowance

For a measured period and job type, calculate F as the return visits that meet your callback definition divided by completed jobs of that type. Calculate R as the total full cost of those return visits divided by the return visits, including labor, travel, and lost capacity. Keep the period and job categories consistent, and exclude unrelated follow-up visits.

Add F times R to the job. Almost everyone skips this move. It separates a price that survives a normal month from one that works only when nothing goes wrong.

If F runs high for a job type, the fix is usually training or truck stock, not a higher price. The sign-off side is in the hiring and training guide.

Move five: margin, and the sanity check

Price equals ((T + D + A) times the recovery rate) plus (C + W + G) plus (F times R), plus the margin you intend to make. State the margin as a decision rather than as whatever is left over, because whatever is left over is not a business model.

In this equation, margin means a target dollar contribution added to the modeled costs. Do not treat a percentage of the selling price as a dollar amount to add.

Only now look at what other shops charge. You are not looking to match them. You are looking for a large gap, which usually means one of you is selling something different: a different response promise, a different scope, or a different set of exclusions.

For the market check, compare offers for the same job type and service area, with similar scope, response terms, parts, warranty, and exclusions. If the prices differ substantially, review your assumptions and what each offer includes before changing your own price.

A job-time illustration

A shop calculates its recovery rate for the quarter. A job comes in twenty-five minutes from base. On site it takes an hour, admin adds a quarter of an hour, and the round trip adds most of an hour. That is roughly two hours of consumed time against a job the customer will call a one-hour repair.

Parts add C, W, and G. The shop's records show this job type returns for a second visit in a small but real fraction of cases, so F times R goes on. The resulting price is noticeably higher than hourly rate times time under the door. That difference is the business surviving.

For this illustration, multiply roughly two hours by the shop’s hourly recovery rate, then add the recorded parts allowance, callback allowance, and target dollar margin. The time figures alone cannot produce a dollar price; that calculation depends on the shop’s own cost and callback records.

Do this on paper for your three most common job types before changing anything. The exercise usually reveals that one of the three has been carrying the other two.

Two things that break the model

The first is quoting before diagnosing. A caller describes a symptom, not a fault, and the door that will not close may need a sensor rather than anything expensive. Price the diagnosis so you are not obliged to guess on the phone.

The second is a scope that was never written down. Time spent negotiating on a driveway is time nobody bills. The fix is a written boundary, not a firmer tone.

Anything you publish about price has to be supportable under the terms the Federal Trade Commission sets out in its advertising guidance for small businesses. A price that arrives with unstated exclusions is where most complaints in this trade begin.

Keeping the inputs honest

Every variable above comes from records: time on site, travel, parts consumed, and outcomes. Keep them in a form you can total, using the IRS summary of records a business should retain as the baseline. Recalculate the recovery rate quarterly, and immediately after any change in insurance, vehicle, or payroll.

Check permit requirements with the local building department and license requirements with the state or local licensing authority responsible for the work in your service area. The licensing and compliance guide explains how to identify local requirements. What you then advertise, and to whom, is the subject of the marketing and growth guide, and the wider structure this pricing sits inside is in the pricing and profit guide.

Common questions

What is a fair margin?

Fair is the one that keeps the business able to replace its vehicle, train its people, and survive a slow month. Any specific percentage quoted without your cost base is decoration.

Should travel be charged separately?

Either charge it or bury it, but count it. Shops that do neither discover the problem only when they expand their service area.

How do I price a job I have never done?

Price the diagnosis, then quote the work with a written trigger for stopping if it is not what you expected. Guessing a fixed price on unfamiliar work is how a shop funds somebody else's education.

What if a customer will not pay the calculated price?

Then it is not your customer for that job. The useful question is whether that is true of most callers or just this one. If it is most, look at the recovery rate and at what you are selling before you look at the price.