How to Build a Plumbing Flat-Rate Price Book Without Expensive Software

Search for how to build a plumbing price book and the results are mostly software companies. They will tell you, at length, that you need their price book product. It costs a few hundred dollars a month. For a two-truck shop, that is a real line item.

You do not need the software to start. You need four things: your true labor cost, the margin divisor formula, a parts markup table, and one organized sheet of prices your techs can pull up on a phone. This post builds all four.

Why flat rate in the first place

Time and materials billing punishes the customer for your efficiency and rewards you for being slow. Flat rate fixes the price before the work starts, so the customer knows what they are paying and you know what you are making. Techs quote with confidence because the number is already decided.

The fear is always the same: what if I price a job flat and it takes twice as long? That happens. It is absorbed by the jobs that come in under time. Flat-rate pricing works on averages, which is exactly why you need the book built from your real costs, not your competitor's prices.

Step 1: Your true labor cost per hour

Take a tech who earns $35 an hour. That is not your cost. Your cost includes:

• Payroll taxes and workers comp: roughly $4 to $6 an hour
• Benefits, uniforms, training: $2 to $4 an hour
• The truck: fuel, insurance, maintenance, depreciation
• Paid non-billable time: drive time, callbacks, shop time, paid days off

Calculate yours once: add up everything a tech costs you in a year, divide by the number of hours that tech actually bills in a year. If a tech is paid for 2,080 hours and bills 1,400, the number is the total cost divided by 1,400.

Step 2: Add overhead per hour

Now take your total annual overhead: office rent, your own pay as the owner, insurance, licenses, software, marketing, the phone bill, everything that is not directly tied to a job. Divide it by the total billed hours of all your techs for the year.

Example: $90,000 in annual overhead divided by 4,200 billed hours across two techs is about $21 per billed hour. A three-hour water heater install carries $63 of overhead.

Step 3: The margin divisor, not a multiplier

This is the step that decides whether the price book makes you money. Most shops add a percentage on top of cost: cost plus 20%. The problem is that 20% markup is not a 20% margin. A $500 cost marked up 20% sells for $600, which is a 16.7% margin. You aimed for 20 and kept 16.7.

The correct formula:

Price = Total Cost / (1 - Target Margin)

If the total cost of a garbage disposal swap is $210 (parts, loaded labor, overhead) and your target margin is 45%, the price is $210 / 0.55 = $382. That number actually keeps 45%. Use a multiplier instead and you quote $252, keeping about 17%, and you wonder why you are busy and broke.

Target margins for plumbing service work: most healthy shops aim for 60 to 70% gross margin on repairs and 40 to 50% on installations like water heaters and repipes.

Step 4: A parts markup table

Parts need a markup schedule because a flat multiplier either overcharges on expensive items or loses money on cheap ones. A common schedule:

• Under $25 (washers, cartridges, supply lines): 4 to 5 times cost. Cheap parts still cost you a truck roll and truck stock.
• $25 to $100 (valves, fittings, flappers): 3 to 4 times cost.
• $100 to $500 (faucets, disposals, toilets): 2.5 to 3 times cost.
• Over $500 (water heaters, softeners): 1.8 to 2.5 times cost. Lower multiplier, still a large dollar margin.

Write the table down. Laminate it. When a tech is tempted to round down "to be nice," the table is the policy that says no.

Step 5: Organize it by category

List your 30 to 50 most common tasks: drain cleaning, water heater installs, toilet rebuilds, faucet replacements, garbage disposals, leak repairs, sewer camera inspections. Group them by category, give each a task code, a one-line scope description, and the flat price from the formula.

The scope line is load-bearing. "Water heater install, 50-gal gas: includes unit, expansion tank, permit, haul-away. Excludes code upgrades to venting and earthquake strapping beyond standard." That sentence prevents the two most common pricing arguments in plumbing.

Step 6: Review it twice a year

Do a full review in January and a mid-year check in July. Once the sheet exists this is a one-afternoon job, because the formulas do the work: update your loaded labor rate, update parts costs, and every price in the book recalculates.

After-hours pricing

Emergency and after-hours work gets its own tier, set in advance: a dispatch fee that is rarely waived, plus a labor multiplier of 1.5 to 2 times. Write it down now, when nobody is calling at midnight.

The price book is the single highest-leverage spreadsheet a plumbing shop can own. It sets every price your techs quote, which means it sets your margin on every job. Build it once, keep it current.

Want the sheet already built with the margin divisor, the loaded-labor calculator, and the markup table wired in? The Contractor Business OS includes a pricing workbook plus the estimator, job-cost tracker, and profit dashboard that shows what each job actually made against its flat-rate price. $119 launch price (list $149).