Terms of Service
Version 2026-09-29c. Effective September 29, 2026. Operator: GICH Holdings LLC, an Arizona limited liability company ("we", "us"). Contact: support@plumbingfixtureunits.com.
1. What this service is
plumbingfixtureunits.com (the "Service") is an online plumbing calculator, available on the website and through an API. It does two things:
- Water supply: estimates demand from water supply fixture units using Hunter's method, suggests a minimum copper pipe size, and can check available pressure.
- Drainage: suggests minimum drain sizes for branches, stacks and the building drain from drainage fixture units, and checks the vent through the roof.
2. A calculator, not an engineering service
The Service applies published formulas and tables to the values you enter. It does not know your project and has not seen your drawings or your site. That means:
- Results are estimates and a minimum-requirements guide for you to check. They are not design values for your project, an engineering design, a code-compliance determination, or professional advice.
- Using the Service does not make us your engineer.
- If a result differs from your contract drawings, the engineer of record's design, or what the local code official requires, those control, not the result.
- You are responsible for what you enter, for checking every result against your drawings and the plumbing code in force where the work is done, and for your own decisions about design, bidding, purchasing and installation.
- Do not use the Service for fire sprinkler, medical gas, process or other specialty systems.
3. Accounts
You must be at least 18 and able to enter a binding contract. If you use the Service for a business, you accept these Terms on behalf of that business.
You sign in with a link we email you, so keep your email account and your API keys secure. You are responsible for activity on your account.
4. Credits and payment
- How credits work. Calculations are paid for with prepaid credits: one completed calculation uses one credit. If the calculator rejects your inputs (for example, a value out of range), no credit is used.
- Prices and tax. Prices are on the Pricing page. Sales tax, where it applies, is added at checkout.
- Who sells to you. Purchases are sold through Link, Stripe's checkout service, which is the merchant of record. Link
collects sales tax, sends your receipt and handles payment support, and its own purchase terms also apply. Your card
statement will show
LINK.COM*. - Your credits. Credits do not expire while the Service is running. They cannot be sold or transferred, and they have no cash value except as the Refund Policy provides.
- Refunds. The Refund Policy has the full details. In short:
- You can get a full refund within 30 days of purchase, once per account in any 12-month period.
- After a full refund, new purchases on that account are paused for 12 months. You can end the pause early with a re-entry purchase (a regular credit pack), which is not refundable.
- A second full refund within 12 months, whether on the same account or on another account with the same payment card, permanently closes every account involved. Any unused credits from other paid purchases are refunded pro rata.
- You can ask us to review any of these decisions.
- If we shut down. If we close the Service for good, we will email you at least 30 days ahead so you can use your remaining credits. Credits bought within 30 days before that notice can be refunded under the Refund Policy.
5. Acceptable use
Do not misuse the Service. That includes trying to break its security, overloading it, scraping it at scale, reselling raw access, or using it to break the law. We may limit API request rates and may suspend accounts that misuse the Service.
6. Our content
The Service, its software and its design belong to us. The public-domain methods and sources it is built on (for example, National Bureau of Standards reports BMS 65, BMS 66 and BMS 79) remain public. Your results are yours to use, print and share.
7. No warranty
THE SERVICE AND ALL RESULTS ARE PROVIDED "AS IS" AND "AS AVAILABLE", WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY AND NON-INFRINGEMENT. We do not warrant that results meet any code, specification or drawing, or that the Service will be uninterrupted or error-free.
8. Limit of liability
TO THE FULLEST EXTENT ALLOWED BY LAW, OUR TOTAL LIABILITY FOR ANY CLAIM ARISING FROM OR RELATING TO THE SERVICE IS LIMITED TO THE AMOUNT YOU PAID US IN THE 12 MONTHS BEFORE THE CLAIM. WE ARE NOT LIABLE FOR INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR PUNITIVE DAMAGES, OR FOR LOST PROFITS, REWORK, DELAY, PROPERTY DAMAGE OR BID LOSSES, EVEN IF WE WERE TOLD THEY WERE POSSIBLE.
9. Indemnity
You agree to defend and indemnify us against third-party claims arising from your use of results in any design, bid, submittal or installation, or from your breach of these Terms.
10. Changes and ending
We may update the Service and these Terms. When the Terms change, we will post the new version here with a new date, and we will email account holders about material changes. You may stop using the Service at any time. We may suspend or end your access if you break these Terms.
11. Governing law
Arizona law governs these Terms, without regard to conflict-of-law rules. Disputes will be heard in the state or federal courts in Maricopa County, Arizona.