Terms of use

These are planning estimates

Every figure this site produces is an estimate for planning. None of it is a quote, a bid, a guarantee of performance, or a professional engineering opinion about your building.

The outputs depend entirely on what you enter. A measurement taken in light rain, a basin dimension read off the lid rather than the liner, or a valuation you guessed at will each produce a confident-looking answer that is wrong, and the site has no way to detect it.

This is not professional advice

We are not your engineer, your plumber, your electrician, or your building inspector. A basement taking water can be a pump problem, a drainage problem, a grading problem, or a structural one, and telling those apart requires somebody on site.

Where the stakes are meaningful — and a finished basement with mechanicals in it is meaningful — get a licensed opinion. Use this site to arrive at that conversation with measurements and questions, which is what it is genuinely good for.

Local rules control

Nothing here overrides your local building code, plumbing code, electrical code, or municipal ordinance. Where this site describes a general principle and your jurisdiction says something different, your jurisdiction is right and this site is not.

This applies with particular force to discharge routing, ground-fault requirements, and permitting, all of which vary between neighbouring municipalities.

Manufacturer data controls

Where this site produces a required flow at a required head, that is a specification to check against a pump's published performance curve. The manufacturer's curve is the authority on what their pump does. Our horsepower banding is a shortlisting aid and is labelled as an assumption throughout.

Follow the installation instructions supplied with any equipment you buy, including details this site does not cover.

Limitation

This site is provided as it is, without warranty of any kind. To the fullest extent the law allows, we accept no liability for loss or damage arising from use of it, including decisions made in reliance on any figure it produced.

If you are in a jurisdiction that does not permit some of that exclusion, the exclusion applies to the greatest extent that jurisdiction does permit.

External links

Links to source documents are provided so you can verify quotes. We do not control those sites and are not responsible for their content or availability. A source that has moved or changed since our retrieval date is exactly what the review process exists to catch, and the contact page is the fastest way to tell us about one.

Use of the site

Use is voluntary and free. You may use the calculators for your own purposes, including commercial ones. Please do not present outputs as though they were an engineering certification, and please do not reproduce the site's content as though it were your own work.