The short answer: price plumbing flat-rate by the fixture, not by the hour. The fixture is the unit a client understands and the unit your own history can price, and it stops hourly billing from punishing you for being fast. Rough-in prices per fixture, service work prices per task, and the diagnostic gets its own honest fee.
A good plumber replaces a kitchen faucet in 40 minutes. A mediocre one takes two and a half hours, fights the corroded nuts, and makes a second trip for a part. Bill both by the hour and the mediocre plumber earns nearly four times as much for the same faucet.
That is the whole argument against hourly pricing in plumbing, compressed into one job. The better you get, the less an hour-priced trade pays you. Plumbing is also the trade where clients are most often in mild distress when they call, least able to evaluate the work, and most sensitive to feeling metered. All three point the same direction: price the job, not the clock.
Why price flat-rate instead of hourly?
Flat-rate pricing means every common task has a set price: faucet replacement, toilet swap, 40-gallon tank water heater changeout, hose bib, sump pump, p-trap rebuild, main shutoff replacement. The price is the same whether it takes you 40 minutes or two hours. It was built from your average time across many jobs, at a rate that pays you properly, plus real materials, plus the costs that hourly plumbers forget to bill anyone for.
Build each flat rate from four parts:
- Average task time, from your own history, including setup and cleanup. Not best case.
- Loaded labor rate. The van, gas, insurance, licensing, tools, callbacks, and the unpaid hours between jobs have to live inside the billed hour. A plumber grossing $150 an hour of paid task time on the tools is often netting a wage once the truck and the empty gaps are paid.
- Materials at replacement cost plus markup, typically 25 to 50 percent on small parts. Brass has opinions about your old price list.
- The trip itself. Every service call carries 30 to 60 minutes of windshield time. Either your flat rates carry a share of it, or you charge an explicit service-call fee that is credited against work performed. The second is cleaner and clients accept it when it's stated up front on the phone.
The result: your speed becomes your margin. The 40-minute faucet at a $329 flat rate pays the good plumber better than any hourly number a homeowner would tolerate, and the client gets certainty, which is what they actually wanted.
The markup vs margin calculator converts one into the other and shows the price and profit behind both.
Where fixtures, not hours, are the unit
For anything bigger than a service call, plumbing prices naturally by the fixture. A bathroom has a per-fixture rough-in and trim cost; a whole house is the sum of its fixtures plus the mains. Renovation plumbers who track their numbers know their per-fixture rough-in figure the way roofers know their per-square rate.
A worked example. A client is adding a basement bathroom: toilet, vanity, one-piece shower, plus a rough-in for a future laundry. Existing 3-inch stack within 12 feet, slab needs breaking for the drains.
- Slab cut, excavation, and below-grade drain runs for three fixtures, backfill and patch-ready: $2,900
- Water supply runs, PEX, with shutoffs at each fixture: $1,150
- Venting tied into the existing stack: $850
- Trim-out: set toilet, install vanity faucet and drain, shower valve and trim: $1,350
- Laundry rough-in box with drain and supplies: $600
- Permit and inspections: $400
Total: $7,250 plus tax and fixtures. Fixtures are the client's choice, supplied by you at cost plus 25 percent or by them with a stated install-only price and no product warranty from your side. The quote states its load-bearing assumption in one line: price assumes the existing stack is serviceable and located as observed; concealed piping found defective will be quoted before work continues.
That sentence earns its place. It is the difference between "we found cast iron rotted past the fitting, here's a signed $1,400 change order" and eating $1,400 because you were embarrassed to reopen the price.
What makes a plumbing job unprofitable?
Access is priced as if every house were new. The flat rate for a shutoff replacement assumes you can reach the shutoff. Crawl spaces, finished ceilings below the work, galvanized that shears when you look at it, a water heater in an attic: each multiplies time. Flat-rate books handle this with access tiers; you can do it with a simple modifier: standard, difficult, and severe access at 1x, 1.5x, and 2x labor. Decide the tier during the walkthrough or the phone triage, not after you're wedged behind a furnace.
Old pipe ambushes. The faucet swap is 40 minutes until the angle stops crumble, and now it's a shutoff replacement too, and the main valve doesn't hold either. Protect yourself two ways: quote the likely companions up front ("if the shutoffs under the sink are original, those are $65 each while I'm in there"), and treat the true surprises as stop-and-approve moments rather than silent absorptions.
Water heaters priced against big-box flyers. The client has seen a tank for $649 and mentally added an hour of labor. Your changeout price carries code items the flyer doesn't: expansion tank where required, pan and drain, venting corrections, permit, disposal of the old tank, and the warranty trip if the unit is defective. Itemize those or lose the job to a price you shouldn't match; a changeout done to code routinely runs $2,200 to $3,500 installed, and the gap from the flyer price is all real.
Emergency work billed at daytime prices. A burst-pipe call at 11 p.m. is worth a premium, and clients in that moment agree. If you offer after-hours service, publish the premium (1.5x labor or a flat after-hours fee) so quoting it never feels like opportunism. If you don't want night work, price it like you mean it or say no; the worst option is doing it resentfully at day rates.
Bidding renovation work for contractors
Service pricing and renovation bidding are different games, and plumbers who play both need to know which table they are sitting at. When a general contractor asks you to price the plumbing on a renovation, your flat-rate service book is the wrong tool. The GC is comparing per-fixture numbers across three plumbers, the schedule is not yours, and the client relationship belongs to someone else.
Bid this work from your per-fixture rough-in and trim rates with the project conditions priced in explicitly. The number that matters to you is not the total; it is the set of assumptions under it, because renovation plumbing is where unstated assumptions go to become free work. State them as bullet points on the quote:
- Number of mobilizations included. A renovation wants you for rough-in, then again weeks later for trim, and every extra "can you just come set the toilet, the flooring got delayed" visit is half a day. Two mobilizations included; extras at a stated trip price.
- Who supplies fixtures, and when they must be on site. A missing shower valve on rough-in day is a schedule failure someone must pay for; say in writing that it will not be you.
- What happens on discovery. Same rule as your own jobs: concealed defects are documented and priced before proceeding, with the GC's signature required, because "just fix it and we'll sort it out" is how plumbers finance other people's renovations.
- Payment terms tied to your milestones, not the project's. Rough-in complete is invoiceable when your rough-in is complete, not when the drywaller eventually closes the walls.
Priced this way, GC work is good work: repeat volume, no marketing cost, predictable scopes. Priced loosely, it is the fastest known method for converting a profitable service company into a busy unprofitable one. If a GC only ever wants your lowest number and none of your terms, that is also information, and the correct bid is a polite pass.
Fixed price versus time-and-materials
The split in plumbing is unusually clean:
- Flat rate / fixed: every routine replacement and every renovation scope you can see and count. This should be the overwhelming majority of your revenue.
- Time-and-materials: drain clearing beyond a simple auger, leak location (not repair), digging to find a supposed line, anything where the problem is not yet defined. Convert to fixed the moment the unknown becomes known.
The phone script for a service call ties it together:
"The service call is $89, and that's credited against any work you approve. When I'm there I'll give you exact prices before touching anything, so you approve every number in advance."
Every sentence lowers the client's guard, and every sentence is also simply true. Diagnose, quote from your flat-rate list on the spot, get the go-ahead, do the work. No meter running, no surprise at the end.
Your flat-rate list has to live somewhere
A flat-rate system is only as good as its list. Prices scribbled in a binder in the van drift out of date, and a plumber quoting from memory rounds down under pressure, every time, in the client's kitchen.
Zeus keeps that list as your Price Book: each task an item with its current price, each quote built by adding items in front of the client, signed on the phone before you open the tool bag. The signature matters more in plumbing than almost any trade, because so much of the work starts within minutes of the price being spoken. A signed quote at 2:15 and a fixed toilet at 3:40 is a clean, indisputable afternoon.
Frequently asked questions
Clients ask for my hourly rate on the phone. What do I say?
Tell them you price by the job so they know the full number before any work starts, and give the service-call structure. "I don't bill open-ended hours; you'll approve a fixed price on the spot" reframes the question from rate-shopping to certainty, which is what most callers actually want. Anyone who insists on comparing hourly rates alone is shopping for the mediocre plumber from the first paragraph.
Should drain clearing be flat-rate?
First-attempt clearing through an accessible cleanout can be flat-rated with a stated scope (one line, one attempt, camera extra). Beyond that, roots, collapsed clay, and mystery blockages are diagnosis, and diagnosis is hourly with equipment fees. Say where the flat rate ends before you start, and offer the camera as the decision tool, not an upsell.
How do I handle client-supplied fixtures?
Install-only price, stated in advance, no product warranty, and a return-trip fee if the fixture is defective out of the box. The client saves money on the fixture and you are protected from the box-store faucet lottery. Refuse nothing; price everything.
What should my service-call fee be?
Enough to cover the round trip and triage even if the client declines all work: commonly $69 to $129 depending on your market and radius, credited against approved work. Waiving it entirely invites tire-kickers; crediting it makes it painless for every serious client.
ZEUS