Shower Fixture Count Calculator

Project inputs

Formula used

This calculator uses a planning-based fixture demand model:

required_showers = ceil((occupancy ÷ persons_per_shower) × peak_factor × redundancy_factor ÷ diversity_factor)

• occupancy ÷ persons_per_shower estimates baseline shower demand.
• peak_factor increases demand during high-use windows.
• redundancy_factor adds spare capacity for outages.
• diversity_factor reduces count when users are not simultaneous.
• accessible_percent sets a minimum accessible share of the total.

How to use this calculator

1. Enter the total occupancy expected to use the showers.
2. Choose a realistic persons per shower planning ratio.
3. Set peak, redundancy, and diversity factors.
4. Decide whether facilities are separate and set male ratio.
5. Press Calculate to view totals and a breakdown.
6. Use Download CSV or Download PDF for sharing.

Demand drivers on active sites

Shower counts are rarely “one-size-fits-all” on construction projects. The highest use typically occurs at shift change, after heavy weather events, or when tasks involve dust, concrete slurry, insulation fibers, or hazardous residues. Treat occupancy as the maximum served headcount, then tune the peak and diversity factors to match how crews actually arrive, finish, and queue. Document the chosen inputs in the project basis-of-design so plumbing, MEP, and site logistics teams can align on staffing forecasts, trailer layouts, and hot-water plant sizing. Revisit the assumptions quarterly as labor plans change.

Occupancy-to-fixture planning ratios

A persons-per-shower ratio translates headcount into baseline demand. As a planning range, 8–12 persons per shower suits industrial worksites with frequent wash-down needs, while 12–20 can fit gyms or sports facilities with staggered use. Dormitory-style shared housing often lands in the middle, but hot water recovery and available floor area may push the ratio higher or lower.

Peak and redundancy allowances

Peak factor covers short windows where demand compresses into minutes. For two shifts with strong overlap, 1.30–1.60 is common; for single shift sites, 1.10–1.25 may be adequate. Redundancy adds resilience when fixtures are offline for cleaning, repairs, or inspections; a 1.05–1.15 allowance can materially reduce downtime impacts.

Simultaneity and diversity adjustment

Diversity factor reduces counts when not everyone showers at the same time. A value of 0.60 implies stronger simultaneity than 0.85. Use lower diversity when crews end together or when the facility is a single central block. Use higher diversity where multiple access points exist and work schedules are distributed.

Example scenario with documented inputs

Example: occupancy 150, persons/shower 12, peak 1.35, redundancy 1.10, diversity 0.70. Baseline demand is 12.50 showers; adjusted demand is 26.52; required fixtures round up to 27. With 6% accessibility target, plan at least 2 accessible showers and verify local requirements.

FAQs

1) Is this a code-compliance tool?

No. It provides a planning estimate based on ratios and demand factors. Always check the adopted plumbing code, owner standards, and accessibility rules before final design.

2) What should I use for persons per shower?

Start with 8–12 for high-contamination worksites, 12–15 for shared residential, and 15–20 for gyms with staggered use. Adjust using site observations and operational constraints.

3) How do I choose the peak factor?

Use 1.10–1.25 for single-shift sites with spread-out departures. Use 1.30–1.60 where most workers finish together, or when weather-driven wash-down events are frequent.

4) What does the diversity factor represent?

It reflects simultaneity. Lower values mean more people showering at once, increasing fixtures. Higher values mean demand is spread out. Typical planning ranges are 0.60–0.85.

5) Why include redundancy?

Fixtures fail or require cleaning and inspection. A redundancy factor builds in spare capacity so short outages do not create long queues or hygiene issues during peak use.

6) How is accessibility handled here?

The calculator sets a minimum accessible count as a percentage of total showers. Final accessibility requirements may depend on facility type, local regulations, and project scope.

7) Should I split fixtures by gender?

If separate facilities are required, enable the split and set the male ratio to match expected users. If facilities are unisex or individual rooms, keep separation off.

Example data table

Example results assume the formula above and rounded-up fixture counts.