Water Usage Calculator (Household / Commercial)

Water planning starts with a number - how many gallons does this household or building actually use a day? That number drives softener sizing, filtration capacity, rainwater tanks, well pumps and water bills.

Water Usage Calculator builds a daily, monthly and annual estimate from occupants, building type and fixture activity so every downstream size has a defensible starting point.

• Residential & commercial: Per-capita baselines for each building type.
• Fixture breakdown: Toilets, showers, laundry, dishwasher, faucets.
• Live update: Daily, monthly and annual totals while you type.
• Dual units: Gallons and litres shown together.
• Export: Text, CSV or JSON report.

1. Pick the building type - household or commercial.
2. Enter occupants and fixture activity.
3. Read the daily total - monthly and annual follow automatically.
4. Export the result to feed into other sizing tools.

Example 1. A family of four with normal fixture use lands around 240-280 gallons per day - roughly 8,500 gallons a month.

Example 2. A 20-person office at the 18-gallon baseline adds about 360 gallons daily - enough to size a modest commercial softener or filtration point of entry.

• Real baseline: A defensible gallons-per-day number.
• Feeds other tools: Softener, filter, tank and pump sizes all start here.
• Dual units: Gallons and litres together.
• Live results: No button presses or page reloads.
• Free and private: No uploads, no logging.