{
  "slug": "water-usage",
  "title": "Water Usage Calculator",
  "heading": "Water Usage Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/water-usage",
  "summary": "Household water use and monthly bill estimate.",
  "description": "Showers, toilets, laundry, and irrigation account for most household water. Swapping to a 1.5 gpm showerhead saves more than almost any other single change.",
  "formula": "Gallons = Sum of each fixture's flow × frequency × household size.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=water-usage",
  "inputs": [
    {
      "id": "people",
      "label": "People in household",
      "kind": "number",
      "hint": null,
      "default": 4,
      "unit": null,
      "min": 1,
      "max": null
    },
    {
      "id": "showerMin",
      "label": "Shower minutes per person per day",
      "kind": "number",
      "hint": null,
      "default": 8,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "showerGpm",
      "label": "Showerhead flow",
      "kind": "number",
      "hint": null,
      "default": 2.1,
      "unit": "gpm",
      "min": 0.5,
      "max": null
    },
    {
      "id": "flushes",
      "label": "Toilet flushes per person per day",
      "kind": "number",
      "hint": null,
      "default": 5,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "flushGal",
      "label": "Gallons per flush",
      "kind": "number",
      "hint": null,
      "default": 1.6,
      "unit": null,
      "min": 0.8,
      "max": null
    },
    {
      "id": "laundry",
      "label": "Laundry loads per week",
      "kind": "number",
      "hint": null,
      "default": 5,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "rate",
      "label": "Water rate",
      "kind": "number",
      "hint": null,
      "default": 6.5,
      "unit": "$/1000 gal",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "monthly",
      "label": "Monthly usage (gallons)",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "cost",
      "label": "Estimated monthly bill",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "daily",
      "label": "Daily usage (gallons)",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "perPerson",
      "label": "Per person per day",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "annual",
      "label": "Annual usage (gallons)",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "People in household: 4",
      "Shower minutes per person per day: 8",
      "Showerhead flow: 2.1 gpm",
      "Toilet flushes per person per day: 5",
      "Gallons per flush: 1.6",
      "Laundry loads per week: 5",
      "Water rate: 6.5 $/1000 gal"
    ],
    "outputs": [
      "Monthly usage (gallons): 5,311.71",
      "Estimated monthly bill: $34.53",
      "Daily usage (gallons): 177.06",
      "Per person per day: 44.3",
      "Annual usage (gallons): 64,625.86"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter people in household.",
      "Enter shower minutes per person per day.",
      "Enter showerhead flow (gpm).",
      "Enter toilet flushes per person per day.",
      "Enter gallons per flush.",
      "Enter laundry loads per week.",
      "Enter water rate ($/1000 gal).",
      "Read your monthly usage (gallons) on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "people": 2,
        "showerMin": 5,
        "showerGpm": 1.26,
        "flushes": 3,
        "flushGal": 0.96,
        "laundry": 3,
        "rate": 6.5
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "people": 4,
        "showerMin": 8,
        "showerGpm": 2.1,
        "flushes": 5,
        "flushGal": 1.6,
        "laundry": 5,
        "rate": 6.5
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "people": 6,
        "showerMin": 13,
        "showerGpm": 3.3600000000000003,
        "flushes": 8,
        "flushGal": 2.5600000000000005,
        "laundry": 8,
        "rate": 6.5
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "How does the water usage calculator work?",
      "a": "Showers, toilets, laundry, and irrigation account for most household water. Swapping to a 1.5 gpm showerhead saves more than almost any other single change. The underlying maths is: Gallons = Sum of each fixture's flow × frequency × household size."
    },
    {
      "q": "What do I need to enter?",
      "a": "7 values: people in household, shower minutes per person per day, showerhead flow, toilet flushes per person per day, gallons per flush, laundry loads per week, and water rate. Each field starts with a sensible default, so you can change one number at a time and watch the result move."
    },
    {
      "q": "What does the monthly usage (gallons) result mean?",
      "a": "It is returned as a whole number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds."
    },
    {
      "q": "Is this calculator free, and do I need an account?",
      "a": "Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser."
    },
    {
      "q": "How accurate is the result?",
      "a": "It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary."
    },
    {
      "q": "Who is this tool for?",
      "a": "It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/electricity-cost",
    "https://www.revenuelab.fyi/toolbox/pool-volume"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Water Usage Calculator (https://www.revenuelab.fyi/toolbox/water-usage)"
}