Toilet Water Rechner — Formel

How to Calculate Toilet Water Usage

Toilets are the single largest indoor water user, accounting for about 24% of household water.

Formula

Annual Gallons = Flushes/Day * GPF * 365

Gallons per Flush by Age

  • Pre-1980 toilets: 5-7 GPF
  • 1980-1994: 3.5 GPF
  • 1994+ federal standard: 1.6 GPF
  • WaterSense (current): 1.28 GPF
  • Ultra low-flow: 0.8-1.0 GPF

    • Lösungsbeispiel

    12 flushes/day with 1.6 GPF toilet at $5/1000 gal water rate.

    1. Daily water: 12 * 1.6 = 19.2 gallons
    2. Annual water: 19.2 * 365 = 7,008 gallons
    3. Annual cost: 7,008 * $5 / 1,000 = $35.04
    4. Savings with 1.0 GPF: (1.6-1.0) * 12 * 365 * $5 / 1,000 = $13.14