PLUMBING CALCULATORS
Built by Plumbers with 50+ Years of Combined Experience
Based on Australian and US Plumbing Standards
Based on US Plumbing Codes
Sewer Slope Calculator
Quickly calculate the minimum slope you need for your drainage and waste pipes. Pick your state, choose your pipe size, enter the run length in feet, hit calculate and get your minimum slope and grade instantly.
Based on the Australian Plumbing Standards
Sewer & Drainage Fall Calculator
Quickly calculate how much fall you need for your drainage and waste pipes. Choose your pipe size, enter the run length in metres, hit calculate and get your minimum fall and grade instantly.
Based on the Australian Plumbing Standards
Fixture Unit & Venting Calculator
Easily work out your fixture units, minimum vent size and minimum drain size in seconds. Select your fixtures, enter your quantities, hit calculate and get your results instantly.
FAQ
Who made these calculators?
Who made these calculators?
These calculators were built by Rebend Industries, a trade tool company founded by plumbers with 50+ years experience on the tools doing the work. We built them because we wanted quick, reliable reference tools that actually work the way tradies think on the job. No signing in or paywalls, just punch in your numbers and get your answer. Save these calculators in your phone for even quicker reference.
Are the calculators free?
Are the calculators free?
Yep, completely free. No account, no email, no catch. We built these as a resource for the trade community because we reckon good information should be accessible to everyone, whether you're a licensed plumber, a first year apprentice, or a homeowner trying to understand what your plumber is talking about.
Do these work for stormwater and sewer?
Do these work for stormwater and sewer?
These calculators are for sewer only. Stormwater generally needs less grade than sewer, so the requirements are different. If enough people reach out and let us know they want a stormwater calculator, we'll get one in the works.
Do these calculators work in all countries?
Do these calculators work in all countries?
Most of our calculators work for both Australia and the USA. The Sewer & Drainage Fall Calculator references Australian and New Zealand plumbing standards, and the Sewer Slope Calculator references US plumbing codes including IPC, UPC and state-specific codes. The Fixture Unit Calculator is built specifically for AS/NZS 3500 and is for Australian use only. We're looking at adding support for other countries down the track, so stay tuned.