1) Effective occupants
EffectiveOccupants = TotalOccupants × PeakFactor × (1 + SafetyAllowance%).
2) Effective occupants-per-fountain ratio
EffectiveRatio = BaseRatio × TierMultiplier. A conservative tier lowers the ratio to increase the count.
3) Per-floor schedule
OccupantsPerFloor = EffectiveOccupants ÷ Floors.
FountainsPerFloor = ceil(OccupantsPerFloor ÷ EffectiveRatio).
TotalFountains = sum(FountainsPerFloor across all floors).
4) Accessibility and fixture mix
AccessibleFountains = ceil(TotalFountains × AccessibleTarget%).
BottleFillers = round(TotalFountains × BottleShare%). StandardFountains = TotalFountains − BottleFillers.
- Enter total occupants based on your design assumptions.
- Choose a building type or enter a custom occupants-per-fountain ratio.
- Set peak factor and safety allowance to reflect project conditions.
- Enter floors served and pick a distribution method for scheduling.
- Set accessible target and bottle filler share for your fixture mix.
- Click Calculate. Use Download buttons for CSV or PDF reports.
| Scenario | Total occupants | Type ratio | Peak | Safety | Floors | Total fountains | Accessible | Bottle fillers |
|---|---|---|---|---|---|---|---|---|
| Office mid-rise | 900 | 1 per 150 | 1.10 | 5% | 6 | 12 | 6 | 5 |
| School wing | 600 | 1 per 50 | 1.00 | 0% | 3 | 12 | 6 | 4 |
| Industrial plant | 1200 | 1 per 200 | 1.15 | 10% | 2 | 16 | 8 | 6 |
Occupant load drives fixture demand
Accurate fountain counts start with a defensible occupant load. Use design occupancy, tenant yield factors, or code-based occupant load values from egress planning. This calculator applies a peak factor to reflect simultaneous use during breaks, shift changes, or event intermissions. A safety allowance adds margin for future growth and reviewer conservatism, converting nominal occupants into effective occupants for sizing. This prevents rework during coordination reviews.
Selecting occupants-per-fountain ratios
Occupants-per-fountain ratios vary by occupancy classification and local amendments, so the calculator offers presets plus a custom option. Start with a ratio for your building type, then apply a conservatism tier to reflect stricter review environments. If your jurisdiction separates fountains by sex, includes outdoor areas, or counts bottle fillers differently, enter an adjusted custom ratio. Document the chosen basis in submissions for traceability.
Floor-by-floor distribution and queuing
Multi-story buildings need more than a single total. The schedule method divides effective occupants across floors, then rounds up per floor to avoid under-provisioning. Choose even distribution when occupancy is uniform, or enforce a per-floor minimum when amenities must exist on every level. Use the per-floor output to coordinate with layouts, chase locations, and routing. Check queuing near cafeterias, gyms, and entrances.
Accessibility and fixture mix planning
Accessibility targets are tracked as a percentage of the total, then rounded up so the minimum is met. Use this output to plan clear floor space, reach ranges, spout heights, and knee clearance, then verify details against accessibility standards. The bottle-filler share estimates how many stations may be integrated as bottle-filling units. Keep some standard fountains where required for access and long term redundancy.
Reporting, coordination, and field verification
Clear documentation speeds approvals and reduces change orders. Use the CSV to paste quantities into schedules, and the PDF to share a snapshot with stakeholders. Pair the results with fixture cut sheets showing key requirements for bottle fillers. During design development, reconcile counts with plumbing fixture tables, occupant load updates, and water quality constraints. Before final turnover, verify installed locations match the floor-by-floor schedule.
Which code does the calculator follow?
It is a planning tool, not a code engine. Select a ratio that matches your adopted plumbing code or authority guidance, then document the basis in your submittal. Always confirm local amendments and project-specific interpretations.
Should I enter total occupants or per-floor occupants?
Enter the total occupants served by the fountain system. The calculator will allocate that demand across floors to create a schedule. If a specific floor has much higher load, run a separate scenario for that zone.
How do I choose a peak factor?
Use 1.00 for steady, distributed use. Use 1.05–1.20 when breaks, shift changes, cafeterias, or assembly events concentrate demand. Choose a value that reflects how quickly occupants will seek water at the same time.
Do bottle fillers replace standard fountains?
Many projects use combined units, but rules differ. The bottle-filler share here is a planning split of the total stations. If your jurisdiction does not allow a filler to substitute for a fountain, keep the share at 0%.
Why can the total increase with more floors?
Because the method rounds up each floor’s requirement, then sums the results. This avoids undercounting when fractional needs exist on multiple floors. It is intentionally conservative for multi-story layouts and plan reviews.
How should I handle outdoor areas or special rooms?
Include those occupants if they will rely on the same fountains, or model them as a separate scenario with an appropriate ratio. Consider proximity, seasonal use, and whether dedicated fountains or bottle fillers are planned for that area.