Count fixtures by space, track unit loads, and spot capacity issues early. Generate clean summaries, download CSV or PDF, and share with teams instantly.
Enter fixture quantities. Add custom fixtures if needed. Values are non‑negative integers.
Sample inputs for a small office core. Use your own plan counts.
| Area | Water closets | Lavatories | Urinals | Showers | Kitchen sinks | Total fixtures |
|---|---|---|---|---|---|---|
| Level 1 | 4 | 4 | 2 | 0 | 1 | 11 |
| Level 2 | 4 | 4 | 2 | 0 | 1 | 11 |
| Break room | 0 | 0 | 0 | 0 | 1 | 1 |
| Total | 8 | 8 | 4 | 0 | 3 | 23 |
1) Total fixture count
Total fixtures = Σ (quantity of each fixture type).
2) Total fixture units
Drainage FU total = Σ (quantity × drainage FU each).
Water FU total = Σ (quantity × water FU each).
3) Planning pipe size estimate
The tool compares total FU against typical threshold ranges to suggest a rough pipe size. Real sizing depends on layout, developed length, pressure, velocity limits, and code tables.
Tip: If you have multiple zones or tenants, run separate calculations and keep a clear scope label.
Fixture counts anchor early plumbing scope, letting teams confirm restroom programs, coordinate cores, and avoid late redesign. A simple schedule of fixtures also supports cost plans, permitting conversations, and bid comparison across alternatives.
Codes assign drainage and water supply fixture units to represent probable peak use. Summing units gives a planning load that is more realistic than counting fixtures alone, especially when multiple fixture types share branches. The approach reflects diversity: not every fixture runs at full flow at the same moment.
In many office projects, a tank water closet is often treated as 4 drainage and 2.5 water units, while a lavatory is commonly 1 and 1. Urinals are frequently around 4 and 2, and showers around 2 and 2. Service sinks and clothes washers can drive both drainage and water loads upward.
Calculate separate totals for tenant suites, cores, kitchens, and amenity floors. This highlights where dedicated stacks or water mains may be needed and prevents one oversized estimate from masking localized high demand. For mixed‑use buildings, keep retail and residential totals separate because usage patterns differ.
Labs, commercial kitchens, or specialty equipment may need different unit values. Use manufacturer data and local tables, then document assumptions in the project name and area fields so reviewers can audit the basis quickly. When unsure, bracket with low and high scenarios to understand sensitivity.
The calculator provides rough pipe size guidance by comparing total units to common threshold ranges. Treat this as a screening tool; final sizing depends on developed length, available pressure, velocity limits, and diversity. After schematic design, confirm sizing with applicable code tables and hydraulic calculations.
Cross‑check counts against plans and occupancy targets, confirm fixture types match specifications, and ensure duplicate schedules are not entered twice. For renovations, separate existing and new fixtures to track scope changes. Also verify whether flush‑valve closets apply in high‑use public spaces.
Share the CSV or PDF with architects, MEP teams, and estimators. A consistent breakdown table improves coordination, accelerates cost updates, and reduces change orders by keeping fixture programs aligned from concept to construction. Include exports in the submittal log to preserve decision history.
They convert fixture counts into a probable demand load for drainage and water supply. Designers use the totals to select preliminary pipe sizes, then verify final sizing with the local code and hydraulic criteria.
Track them separately. Enter existing fixtures for context, then create a second run for new work only. This keeps scope clear and helps estimators, reviewers, and inspectors understand what changes.
Public rooms often use flush‑valve closets and higher‑use patterns. Confirm fixture type, apply the correct unit values, and consider splitting calculations by floor or zone so peak areas are visible.
They are screening estimates based on common threshold ranges. Final sizes depend on layout, developed length, pressure, velocity limits, and specific code tables for water distribution and drainage.
Use them for lab sinks, commercial equipment, special rinse stations, or any fixture where your code table assigns different unit values. Document the source of the units in your project notes.
Yes. Run the calculator once per tenant or zone and label each export. Comparing reports quickly reveals which areas drive water and drainage loads and where separate mains or stacks are justified.
After calculating, download the CSV for spreadsheets or the PDF for quick review. Attach exports to meeting notes or submittals so everyone references the same fixture schedule and assumptions.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.