Quick answer: NBC India 2016 (Part 9) sets the minimum sanitary fixtures — water closets, urinals and wash basins — per number of occupants, separately for males and females and by building type (office, mercantile, assembly, industrial). You divide the occupant load by the code ratio for each fixture and round up.
How fixture requirements work
NBC Tables give ratios such as "1 WC per 25 females" or "1 urinal per 25 males" for offices. The designer counts occupants, splits by gender, and applies the ratio for each fixture type.
Steps
- Determine total occupancy (from area ÷ occupant-load factor, or client data).
- Split into male/female (often 50:50 unless known).
- Apply the NBC ratio for WCs, urinals and basins by building type.
- Round each up to a whole fixture.
Worked example
Office with 100 occupants (50 M / 50 F). At ~1 WC per 25: females need 2 WCs, males 1 WC + 2 urinals; wash basins ~1 per 25 → 2 each. Always confirm against the current NBC table for the exact occupancy.
Enter occupancy and building type — get required WCs, urinals and basins per NBC 2016. Free.
Open the NBC Plumbing Calculator →Frequently Asked Questions
How many toilets are required per person as per NBC?
NBC India 2016 sets ratios by building type — for offices roughly 1 water closet per 25 persons, adjusted by gender split, plus urinals for males and wash basins. Assembly and mercantile buildings use different ratios.
Does NBC require separate male and female facilities?
Yes. NBC specifies fixtures separately for males and females, and larger buildings also require accessible fixtures for persons with disabilities.