{
  "slug": "pool-gallons-kidney-calculator",
  "title": "Kidney Pool Gallons Calculator",
  "heading": "Kidney Pool Gallons Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/pool-gallons-kidney-calculator",
  "summary": "Estimate total gallons for a curved kidney-shaped in-ground pool.",
  "description": "Kidney-shaped pools are a popular in-ground design prized for their curved, organic footprint, but that same curve makes exact volume math harder than a simple rectangle or circle. The standard industry approximation treats a kidney pool as two overlapping circles' worth of area using its two width measurements (taken at the widest points of each lobe) averaged together with the pool's overall length, then multiplied by depth and a shape correction factor of roughly 0.45 in place of a full rectangle's implied area. This calculator takes the two width measurements, overall length, and average depth (from shallow to deep end) to return an estimated gallon count that pool professionals commonly use for chemical dosing on kidney and free-form pools where a perfectly precise formula isn't practical. Because kidney pools are irregular, this is always an estimate — for exact volume, a pool service can calculate from as-built architectural drawings — but it's accurate enough for day-to-day chemical balancing.",
  "formula": "Gallons = Length × ((Width1 + Width2) ÷ 2) × Average Depth × 7.5 × 0.85",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=pool-gallons-kidney-calculator",
  "inputs": [
    {
      "id": "length",
      "label": "Length",
      "kind": "number",
      "hint": null,
      "default": 30,
      "unit": "ft",
      "min": 5,
      "max": 60
    },
    {
      "id": "width1",
      "label": "Width at widest point 1",
      "kind": "number",
      "hint": null,
      "default": 16,
      "unit": "ft",
      "min": 3,
      "max": 40
    },
    {
      "id": "width2",
      "label": "Width at widest point 2",
      "kind": "number",
      "hint": null,
      "default": 12,
      "unit": "ft",
      "min": 3,
      "max": 40
    },
    {
      "id": "avgDepth",
      "label": "Average depth",
      "kind": "number",
      "hint": null,
      "default": 4.5,
      "unit": "ft",
      "min": 1,
      "max": 12
    }
  ],
  "outputs": [
    {
      "id": "gallons",
      "label": "Estimated pool gallons",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "avgWidth",
      "label": "Average width",
      "format": "decimal",
      "hint": "ft",
      "primary": false
    },
    {
      "id": "cubicFeet",
      "label": "Estimated cubic feet",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Length: 30 ft",
      "Width at widest point 1: 16 ft",
      "Width at widest point 2: 12 ft",
      "Average depth: 4.5 ft"
    ],
    "outputs": [
      "Estimated pool gallons: 12,049",
      "Average width: 14",
      "Estimated cubic feet: 1,607"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter length (ft).",
      "Enter width at widest point 1 (ft).",
      "Enter width at widest point 2 (ft).",
      "Enter average depth (ft).",
      "Read your estimated pool 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": {
        "length": 18,
        "width1": 10,
        "width2": 7,
        "avgDepth": 2.6999999999999997
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "length": 30,
        "width1": 16,
        "width2": 12,
        "avgDepth": 4.5
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "length": 48,
        "width1": 26,
        "width2": 19,
        "avgDepth": 7.2
      }
    }
  ],
  "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": "Why is there a 0.85 correction factor?",
      "a": "Kidney and free-form pools have curved edges that hold less water than a full rectangle of the same overall length and width, so pool professionals apply a shape correction factor, commonly 0.85, to approximate the actual curved area more accurately."
    },
    {
      "q": "How accurate is this estimate compared to a rectangular pool calculation?",
      "a": "It's an approximation rather than an exact figure — typically within 10-15% of true volume — which is accurate enough for chemical dosing but not for precise engineering or water-loss leak calculations."
    },
    {
      "q": "Where do I measure the two widths on a kidney pool?",
      "a": "Measure straight across at the widest point of each of the pool's two curved lobes, which is usually near each rounded end of the kidney shape rather than at the narrow waist in the middle."
    },
    {
      "q": "Can I get an exact volume for my custom pool?",
      "a": "Yes, your pool builder's as-built drawings or a pool service company can calculate exact volume from the actual excavation plans, which is worth requesting if you need precise numbers for equipment sizing rather than chemical dosing."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/pool-gallons-oval-calculator",
    "https://www.revenuelab.fyi/toolbox/pool-gallons-round-calculator",
    "https://www.revenuelab.fyi/toolbox/pool-shock-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Kidney Pool Gallons Calculator (https://www.revenuelab.fyi/toolbox/pool-gallons-kidney-calculator)"
}