{
  "slug": "mpg",
  "title": "MPG Calculator",
  "heading": "MPG (Fuel Economy) Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/mpg",
  "summary": "Miles per gallon, L/100km, and cost per mile from a fill-up.",
  "description": "Measure economy across a full tank, not a single trip: fill up, reset the trip meter, then divide miles driven by gallons at the next fill for a real number.",
  "formula": "MPG = Miles driven ÷ Gallons used; L/100km = 235.215 ÷ MPG.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=mpg",
  "inputs": [
    {
      "id": "miles",
      "label": "Miles driven since last fill",
      "kind": "number",
      "hint": null,
      "default": 320,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "gallons",
      "label": "Gallons to refill",
      "kind": "number",
      "hint": null,
      "default": 11.4,
      "unit": null,
      "min": 0.1,
      "max": null
    },
    {
      "id": "price",
      "label": "Price per gallon",
      "kind": "number",
      "hint": null,
      "default": 3.6,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "mpg",
      "label": "Miles per gallon",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "l100",
      "label": "Liters per 100 km",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "kmL",
      "label": "Kilometers per liter",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "costPerMile",
      "label": "Fuel cost per mile",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "fillCost",
      "label": "Cost of this fill-up",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "per100",
      "label": "Fuel cost per 100 miles",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Miles driven since last fill: 320",
      "Gallons to refill: 11.4",
      "Price per gallon: 3.6 $"
    ],
    "outputs": [
      "Miles per gallon: 28.07",
      "Liters per 100 km: 8.38",
      "Kilometers per liter: 11.93",
      "Fuel cost per mile: $0.128",
      "Cost of this fill-up: $41.04",
      "Fuel cost per 100 miles: $12.83"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter miles driven since last fill.",
      "Enter gallons to refill.",
      "Enter price per gallon ($).",
      "Read your miles per gallon 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": {
        "miles": 190,
        "gallons": 6.84,
        "price": 2.16
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "miles": 320,
        "gallons": 11.4,
        "price": 3.6
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "miles": 510,
        "gallons": 18.240000000000002,
        "price": 5.760000000000001
      }
    }
  ],
  "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 mpg (fuel economy) calculator work?",
      "a": "Measure economy across a full tank, not a single trip: fill up, reset the trip meter, then divide miles driven by gallons at the next fill for a real number. The underlying maths is: MPG = Miles driven ÷ Gallons used; L/100km = 235.215 ÷ MPG."
    },
    {
      "q": "What do I need to enter?",
      "a": "3 values: miles driven since last fill, gallons to refill, and price per gallon. 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 miles per gallon result mean?",
      "a": "It is returned as a decimal 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/gas-trip-cost",
    "https://www.revenuelab.fyi/toolbox/cost-per-mile",
    "https://www.revenuelab.fyi/toolbox/ev-vs-gas"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — MPG Calculator (https://www.revenuelab.fyi/toolbox/mpg)"
}