Terms of use
Last updated: 2026-09-19
By using TanklessCalc you accept these terms. If you do not accept them, please do not use the site.
What this site provides
The tools here perform arithmetic on the values you enter, using published constants, conventional coverage figures and standard formulas. They are free to use, need no account, and run entirely in your browser.
The limits of the results
- Results are estimates based on what you type in. They are not measurements.
- They are not professional advice, not legal, medical, financial, engineering, architectural or safety advice. Sizing results are planning estimates from published fixture flow rates and physical constants, not an assessment of a specific building.
- Published constants and product coverage figures vary between manufacturers and editions. Where they do, the site says so on the page rather than picking one silently.
- Nothing here accounts for your specific circumstances: your site conditions, your local code, your materials, or your skill.
Gas, venting and electrical work
A tankless heater usually needs a larger gas line than the tank it replaces, its own venting, and in the electric case a service upgrade that can cost more than the unit. Gas piping, combustion venting and electrical work are regulated in most jurisdictions and getting them wrong causes fires, carbon monoxide poisoning and electrocution. Nothing here is installation guidance. Have the work done by a licensed contractor and inspected where your jurisdiction requires it.
Incoming water temperature is an estimate
The per-state incoming water temperatures on this site are guidance based on the relationship between shallow groundwater and mean annual air temperature. They are not measurements of your supply, and a municipal supply drawn from a surface reservoir can run colder in winter than the table suggests. Measure your own cold tap with a thermometer in the coldest month before committing to a unit.
Your responsibilities
- Verify any figure against your own measurements and, where it matters, a qualified professional.
- Confirm anything governed by regulation, building codes, permits, food safety, medical practice, accessibility requirements, with the authority that publishes it.
- Check your own product labels for coverage and application instructions.
No warranty
The site is provided "as is" and "as available", without warranty of any kind, express or implied, including fitness for a particular purpose. We do not warrant that the site will be uninterrupted, error-free, or that any result is accurate for your situation.
Limitation of liability
To the fullest extent permitted by law, we are not liable for any indirect, incidental or consequential loss arising from your use of this site, including materials over- or under-ordered, work redone, wasted product, or damage to property. Where liability cannot be excluded, it is limited to the amount you paid to use the site, which is nothing.
Your content and your data
Anything you type into a tool remains yours and stays in your browser. You grant us no licence over it, because we never receive it.
Acceptable use
Do not attempt to disrupt the site, scrape it at a volume that degrades service for others, or present its output as professional advice to a third party.
Third-party links
Links to other sites are provided for convenience. We do not control them and are not responsible for their content, products or privacy practices.
Changes
These terms may change; the date above will change with them. Continued use after a change means you accept the revised terms.
Governing law
These terms are governed by the laws of the operator’s principal place of business, without regard to conflict-of-law rules.