About this tool

Who writes this

Andrew Flores, working alone, with AI assistance used for drafting and checking and never as a source. He runs this site and answers for its corrections. The four sourced constants name their source and the date of the saved copy they were checked against; the others carry a visible derived or assumed label.

Nathan Management publishes this site from California, and builds single-purpose calculators rather than general home-improvement pages. We are not contractors, not plumbers, not licensed in any trade, and not affiliated with any pump manufacturer, retailer, or installer network.

Why it works the way it does

Most tools in this category ask the visitor for horsepower or for gallons per hour and then multiply by a price. That is backwards. Somebody searching for a sump pump calculator does not know what horsepower they need — the entire reason they are searching is to find out. A tool that requires the answer as an input has not helped anyone.

So this site derives capacity from things a person can observe: how wide the basin is, how fast the water rose while they timed it, how high the discharge goes and how far it runs. The output is a specification — a required flow at a specific total head — that can be checked against any manufacturer's published performance curve.

The position on prices

We do not publish a national installed price for a sump pump, and that is a deliberate choice rather than an oversight. Installed pricing depends on which items a particular basement requires — basin work, discharge rerouting, whether an electrician is needed — and by local labour rates. A national average would look authoritative without being true for anybody in particular.

Instead, the install page derives the scope: the specific line items your answers imply, flagged for which ones are worth confirming line by line. That is something a calculator can honestly do, and it is more useful when you are holding two quotes that differ by a large margin.

Where a money figure is sourced — the national electricity rate is the only one — it is labelled and linked. Every other dollar value on this site is either one you enter or an illustrative starting value, labelled as such.

Where the numbers come from

The load-bearing constants are federal: the United States Geological Survey for the rainfall-to-volume conversion, and the Energy Information Administration for residential electricity pricing. Unit conversions are derived from definitions and the arithmetic is published. The remaining registered constants are labelled assumptions with disclosures, and the screening thresholds the tools use are listed on the methodology page.

The full list, with sources and dates, is on the methodology page, along with a table of the figures we deliberately decline to publish and the reason for each.

What we do not do

• We do not rank or recommend specific pump models. We have no independent reliability evidence and will not manufacture the impression that we do.
• We do not accept payment for placement, and there is no arrangement under which a manufacturer could influence what appears here.
• We do not collect your calculator inputs. The tools run entirely in your browser and nothing you type is transmitted anywhere.
• We label every registered figure sourced, derived, or assumed, and we list the thresholds the tools use.

What this site cannot do for you

It cannot see your basement. Every output rests on what you enter, and the tools are explicit about which inputs matter most — the sizing tool names its biggest swing factor on the page rather than burying it.

It also cannot tell you what your jurisdiction permits. Discharge routing, electrical requirements, and permitting differ from one municipality to the next, and the honest answer to most of those questions is a phone call to your building department. The discharge page lists the five questions worth asking.

And it is not a substitute for a licensed opinion about your building. A basement taking water is sometimes a pump problem and sometimes a drainage problem, and a larger pump applied to a drainage problem is an expensive way to keep the symptom running.