{
  "slug": "18-ft-round-pool-gallons-calculator",
  "title": "18 Ft Round Pool Gallons Calculator",
  "heading": "18 Ft Round Pool Gallons Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/18-ft-round-pool-gallons-calculator",
  "summary": "Water volume in gallons for an 18-foot round above-ground pool.",
  "description": "18-foot round is a popular above-ground pool size. This calculator defaults to that diameter with a 4-foot average depth and returns total gallons, which is the key number for sizing pumps, filters, and chemical dosing on a circular pool.",
  "formula": "Gallons = π × (Diameter ÷ 2)² × Average Depth × 7.48.",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=18-ft-round-pool-gallons-calculator",
  "inputs": [
    {
      "id": "diameter",
      "label": "Pool diameter",
      "kind": "number",
      "hint": null,
      "default": 18,
      "unit": "ft",
      "min": 5,
      "max": null
    },
    {
      "id": "avgDepth",
      "label": "Average depth",
      "kind": "number",
      "hint": null,
      "default": 4,
      "unit": "ft",
      "min": 2,
      "max": 10
    }
  ],
  "outputs": [
    {
      "id": "gallons",
      "label": "Total water volume",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "cubicFeet",
      "label": "Total cubic feet",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Pool diameter: 18 ft",
      "Average depth: 4 ft"
    ],
    "outputs": [
      "Total water volume: 7,614",
      "Total cubic feet: 1,018"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter pool diameter (ft).",
      "Enter average depth (ft).",
      "Read your total water volume 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": {
        "diameter": 11,
        "avgDepth": 2.4
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "diameter": 18,
        "avgDepth": 4
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "diameter": 29,
        "avgDepth": 6.4
      }
    }
  ],
  "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 many gallons is an 18-foot round pool?",
      "a": "At a 4-foot average depth, about 7,616 gallons — a common figure used to size filter pumps and calculate chlorine dosing."
    },
    {
      "q": "Does an above-ground pool have a uniform depth?",
      "a": "Most do, unlike in-ground pools with a deep end, so the average depth is usually just the wall height minus a few inches for the waterline."
    },
    {
      "q": "How often should I test water in a pool this size?",
      "a": "Two to three times per week during swim season is standard for above-ground pools this size, more often after heavy rain or heavy use."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/16x32-pool-gallons-calculator",
    "https://www.revenuelab.fyi/toolbox/15x30-oval-pool-gallons-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — 18 Ft Round Pool Gallons Calculator (https://www.revenuelab.fyi/toolbox/18-ft-round-pool-gallons-calculator)"
}