Water supply calculation (PPR): selecting the pipe diameter in 1 minute

Water supply calculation (PPR): selecting the pipe diameter in 1 minute

What PPR pipe diameter should be installed? Calculate it in one minute.

You are a plumber. You know: after the meter, a 20 mm PPR pipe is typically used. But if there are two bathrooms, three, or high-powered equipment, a 20 mm pipe may not be enough. And manual calculations are time-consuming and tedious.

This calculator solves the problem. Enter the fixtures and get a ready-made answer: which diameter to install.

What it calculates:

Total flow rate (L/min, m³/h)

Recommended PPR pipe diameter (20, 25, 32, 40 mm)

Explanation of what this diameter means

Why it is convenient:

Simple. Enter the number of fixtures and get an answer.

Practical. Logic aligned with real-life usage: up to 20 L/min → 20 mm pipe, up to 35 L/min → 25 mm pipe, up to 60 L/min → 32 mm pipe.

Fast. Calculations done in one minute instead of manual estimations.

Protected. Formulas are hidden, so buyers cannot tamper with them.

What’s included:

Excel calculator (auto-calculates).

Instruction on how to use it.

Who is it for:

Plumbers — to select the correct diameter on-site.

Handymen — for quick checks.

Anyone doing renovations — to understand what the crew is doing.

Important: Flow rates in the table are averages according to SP 30.13330. Pressure is measured via a gauge. If there is no water flow, this will be obvious immediately — such cases are beyond the scope of this calculation.