Pump Head Calculator
Calculate static head, pressure head, friction loss, velocity, and total dynamic head.
Open ToolWater Demand Calculator
A domestic water demand calculator for occupancy, per-person usage, fixture peak load, diversity, and short-term storage planning.
Inputs
Forms are empty on load. Use sample data to preview the workflow or enter your own project values.
Learn more
Formula logic, use cases, assumptions, and limits for this tool.
How this tool helps
Use this to estimate domestic water demand and check whether fixture peak and daily demand are aligned.
Assumptions and limits
This tool provides a planning-level result. It does not replace detailed engineering design, approved software, manufacturer data, authority requirements, or project specifications.
Typical use cases
- Early estimation and tender support.
- BOQ sanity checking and technical review.
- Site discussion before final engineering verification.
- Comparison of alternatives using consistent assumptions.
Result interpretation
Read the recommendation, warning, and confidence sections together. A result without warnings is still not an approval; it only means the entered values did not trigger built-in planning alerts.
Input definitions and typical values
These notes explain what each input means and which values usually produce a more reliable planning result.
Occupants people
Expected number of people using the space. Use realistic peak occupancy, not only average daily occupancy.
Demand per person L/person/day
Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.
Fixture peak flow before diversity L/min
Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.
Diversity factor %
Percentage of connected load expected to operate at the same time. Use project schedules; 60-90% is common in many planning checks.
Storage duration hours
Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.
Practical verification checklist
- Confirm the selected standard profile is suitable for the project location and authority.
- Replace sample values with project drawings, schedules, equipment data, or measured site values.
- Review warnings, methodology, and PDF report before using the result outside early planning.
- Verify final decisions against official standards, manufacturer data, consultant specifications, and local approvals.
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Open ToolCalculation methodology
Daily demand and peak flow are estimated from occupancy, per-person consumption, fixture peak, diversity, and storage duration.
Inputs are treated as planning assumptions. The calculator shows warnings when entered values fall outside practical thresholds or selected standard-profile limits.
Version history
- v1.3.6-prelaunch: Added methodology, standard profile support, version notes, and direct PDF report download.
- v1.3.5: Calculator page added with sample data, warnings, and print-ready report layout.
Stage 2 roadmap: optional saved projects, dashboards, and shared calculation history without forcing login for free use.
Trust and verification
Every result includes assumptions, warning logic, and a downloadable report. Final engineering decisions still need qualified review, local authority approval, manufacturer data, and project specifications.
Worked example
Use the sample data button to load a realistic scenario, then download the PDF report to review inputs, results, methodology, warnings, and disclaimers in one place.