Worked examples
Two households, run all the way through the tools
There is no hand-typed dollar figure or flow number on this page. Every stat below comes straight out of this site's own calculators — sizing, operating cost, backup runtime, install scope, and failure exposure, the same eight tools you can fill in yourself — run once each against a described example household. Change the household description and every number on the page changes with it, because one calculator produces both the live tool and this page.
Two households, chosen to sit on opposite ends of the site's own range: a first-time install with no measurement yet, and a replacement job on a finished basement with several things wrong with it. Read them as demonstrations of the method, not as a description of your house — the whole point of the eight tools is that your inputs replace these.
Household A — first-time install, unfinished basement, no measurement yet
A split-level with a bare concrete basement and no existing pit. Nobody has timed a rise here, so the sizing tool falls back to the estimate path: 2,200 sq ft of roof and driveway draining toward the foundation, at the sitewide placeholder rain intensity of 1.0 in/hr, a 7-inch float drawdown in an 18-inch pit, 8 ft of lift and 35 ft of discharge run on 1.5-inch pipe with a swing check.
Shopping spec: Deliver at least 12.0 gallons per minute (720 gallons per hour) at 8.7 feet of total head.
Inflow, low to high 2.3 to 16.0 gpm
Cycling at this inflow: about 116 seconds running and 58 seconds resting, or roughly 21 starts an hour, from a 1.10-gallon-per-inch pit with the drawdown entered above.
| Downstream tool | Input taken from the sizing result | What it returned |
|---|---|---|
| Operating cost | Pump flow 12.0 gpm at this head, 400 W (an assumed wattage for the 1/4 HP class band), the sourced EIA rate, assumed water arriving 70 days a year for 6 hours at a time | $20.65/yr (280 run hours, 112.0 kWh) |
| Battery backup | 100 Ah, 1 yr old, backup pump drawing 10 A and moving 14 gpm against this same inflow, checked against a 6-hour outage | 8.1 hours runtime, duty cycle 57%, covers the 6-hour outage entered |
| Install scope | Basin condition, existing circuit, check valve, and discharge answers for this household | 7 required line items, permit likely, electrician likely needed |
| Failure exposure | Unfinished, $4,000 contents, $6,000 mechanicals at risk, not covered by policy, longest outage 8 hr (2/yr), a single pump/float/circuit with no redundancy | Battery backup plus a second primary pump staged higher in the pit — $10,000 out of pocket on those numbers |
The scope tool's own required lines for this household: The pump itself, matched to the flow and head this site derived; Break the slab, excavate, and set a new basin; Check valve on the discharge; Run a dedicated circuit and receptacle for the pump; Trace where the discharge actually terminates; Freeze protection at the discharge termination; High-water alarm.
Of those, Check valve on the discharge, Trace where the discharge actually terminates, Freeze protection at the discharge termination, and High-water alarm are the lines a lowball quote most often leaves out — see how to read a quote for what to do with that.
Household B — replacing a failing pump, finished basement, four known defects
A walk-out basement finished into a family room, with an existing pump the owner is replacing after it started running constantly without clearing the pit. This household has a real measurement: 6 inches of rise in 45 seconds in a 22-inch pit, against 11 ft of lift and 55 ft of run. The install-scope answers describe what the last contractor left behind: a pit too small for this load, a circuit with no ground-fault protection, no check valve, and a discharge that currently ties into the sanitary line.
Shopping spec: Deliver at least 19.7 gallons per minute (1185 gallons per hour) at 13.6 feet of total head.
Inflow, low to high 11.2 to 15.1 gpm
Cycling at this inflow: about 135 seconds running and 68 seconds resting, or roughly 18 starts an hour, from a 1.65-gallon-per-inch pit with the drawdown entered above.
| Downstream tool | Input taken from the sizing result | What it returned |
|---|---|---|
| Operating cost | Pump flow 19.7 gpm at this head, 400 W (an assumed wattage for the 1/4 HP class band), the sourced EIA rate, assumed water arriving 110 days a year for 9 hours at a time | $48.68/yr (660 run hours, 264.0 kWh) |
| Battery backup | 100 Ah, 5 yr old, backup pump drawing 12 A and moving 18 gpm against this same inflow, checked against a 16-hour outage | 3.4 hours runtime, duty cycle 73%, falls 12.6 hr short of the 16-hour outage entered |
| Install scope | Basin condition, existing circuit, check valve, and discharge answers for this household | 6 required line items, permit likely, electrician likely needed |
| Failure exposure | 600 sq ft finished, $9,000 contents, $26,000 finishes, $8,000 mechanicals at risk, $2,500 deductible, covered, longest outage 16 hr (4/yr), some redundancy already in place | Battery backup pump with its own alarm — $2,500 out of pocket on those numbers |
The scope tool's own required lines for this household: The pump itself, matched to the flow and head this site derived; Enlarge or replace the existing basin; Check valve on the discharge; Ground-fault protection at the receptacle; Reroute the discharge off the sanitary sewer; Backup pump, battery, charger, and alarm.
Of those, Enlarge or replace the existing basin, Check valve on the discharge, and Ground-fault protection at the receptacle are the lines a lowball quote most often leaves out — see how to read a quote for what to do with that.
Reading the two side by side
The comparison worth making is not "which household pays more" — it is which number moved because of a real difference in the inputs, and which didn't. Required flow tracks inflow almost exactly, because both are the same inflow times the same 1.5x margin: Household A's estimated 8.0 gpm needs 12.0 gpm; Household B's measured 13.2 gpm needs 19.7 gpm. Head is a separate number — B's 13.6 ft against A's 8.7 ft comes from a longer, higher-lift run — and it changes what pump can deliver that flow, not how much flow is required in the first place.
Operating cost does NOT follow the inflow gap. Required flow is always inflow times the same margin, so inflow cancels out of the run-hour math entirely — a check worth doing: substitute B's inflow and required flow into A's assumed wet-weather duty and the answer comes back unchanged. What actually separates $20.65 a year for A from $48.68 for B is the OTHER assumption each household carries: A assumes water arrives on 70 days a year for 6 hours at a time (420 hours total); B assumes a wetter year, 110 days at 9 hours (990 hours total) — 2.36x the duty, which is exactly the cost ratio. Both figures are still small enough in absolute terms that neither household should let electricity decide anything.
Scope and exposure are where the households genuinely diverge. A's from-scratch install requires 7 lines: a brand-new basin, a new dedicated circuit, tracing an unknown discharge, freeze protection, and a high-water alarm, on top of the pump and check valve every job needs. B's replacement requires 6: enlarging an undersized basin, adding ground-fault protection to a circuit that already exists, rerouting a discharge that is known to be wrong, and a backup system (which carries its own alarm), on top of the same pump and check valve. Similar line counts, genuinely different work — which is exactly what price drivers goes into.
Reproduce this with your own numbers
Nothing here is special-cased. Open the sizing calculator, enter your own pit, your own timed rise or your own catchment estimate, and your own discharge route, and you will get the same kind of output this page built for two hypothetical households — because it is the same calculator. Carry the flow-at-head result into operating cost and backup runtime, and carry your own basin and discharge answers into install scope and failure exposure, exactly as this page did.