Pipe Network Headloss Calculator
Calculate head loss and pressure drop for pipes in series or parallel branches using Darcy–Weisbach — get the flow split, velocity, Reynolds number and friction factor for every pipe.
Input
One pipe per line. Roughness defaults to 0.045 mm (steel), K (minor-loss coefficient) to 0.
Water at 20 °C ≈ 1.004 mm²/s; at 60 °C ≈ 0.475.
Used only to convert head loss to pressure drop.
Output
| Metric | Value |
|---|---|
| No data yet | |
| Pipe | Flow (L/s) | Velocity (m/s) | Reynolds | Friction f | Head Loss (m) |
|---|---|---|---|---|---|
| No data yet | |||||
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/pipe-network-headloss-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"layout": "series",
"pipes": "100, 100, 0.045, 1.5\n50, 80, 0.045, 0.5",
"flow": "10",
"viscosity": "1.004",
"density": "998"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `pipe-network-headloss-calculator` tool (Pipe Network Headloss Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/pipe-network-headloss-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Pipe Network Headloss Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
What this pipe network headloss calculator does
Real piping is rarely one pipe. This tool calculates the head loss and pressure drop of several pipes joined in series, or of parallel branches sharing a flow. For every pipe you get its flow, velocity, Reynolds number, friction factor and head loss, plus the total for the network.
How to use it
Pick series or parallel. List one pipe per line as length (m), diameter (mm), roughness (mm), K — roughness defaults to 0.045 mm (commercial steel) and K, the minor-loss coefficient for fittings and valves, defaults to 0. Enter the total flow, fluid viscosity and density. Results update as you type.
How it's calculated
Head loss h = (f · L/D + K) · v² / 2g (Darcy–Weisbach)
Friction f = 64/Re (laminar), Swamee–Jain (turbulent)
Series every pipe carries the full flow; losses add
Parallel flow splits so every branch has the same head lossIn parallel mode the tool solves for the common head loss at which the branch flows add up to the total flow.
Screening tool. It treats each pipe independently and doesn't model loops with shared nodes, pumps or elevation changes. Use it for quick sizing and have a qualified engineer check critical designs.
Frequently asked questions
Why is a smaller parallel branch carrying less flow? Head loss rises steeply with velocity and falls with diameter, so the wider, shorter branch takes the larger share until losses equalize.
What K value should I use? Typical values: 90° elbow 0.3–0.9, gate valve (open) 0.2, globe valve 10, pipe entrance 0.5, exit 1.0. Add them up per pipe.