{
  "slug": "age-calculator",
  "title": "Age Calculator",
  "heading": "Age Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/age-calculator",
  "summary": "Exact age in years, months, days, hours, and next birthday.",
  "description": "Counts your exact age accounting for leap years, plus the countdown to your next birthday and total days lived.",
  "formula": "Age = whole years, months, and days elapsed since the birth date.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=age-calculator",
  "inputs": [
    {
      "id": "birth",
      "label": "Date of birth",
      "kind": "date",
      "hint": null,
      "default": "1990-06-15"
    },
    {
      "id": "asOf",
      "label": "As of date",
      "kind": "date",
      "hint": null,
      "default": null
    }
  ],
  "outputs": [
    {
      "id": "age",
      "label": "Exact age",
      "format": "raw",
      "hint": null,
      "primary": true
    },
    {
      "id": "years",
      "label": "Age in whole years",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "nextBirthday",
      "label": "Days until next birthday",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "totalDays",
      "label": "Total days lived",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "weeks",
      "label": "Total weeks lived",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "totalHours",
      "label": "Total hours lived",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Date of birth: 1990-06-15",
      "As of date: 2026-09-30"
    ],
    "outputs": [
      "Exact age: 36 years, 3 months, 15 days",
      "Age in whole years: 36",
      "Days until next birthday: 258",
      "Total days lived: 13,256",
      "Total weeks lived: 1,893",
      "Total hours lived: 318,144"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter date of birth.",
      "Enter as of date.",
      "Read your exact age 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": {
        "birth": "1990-06-15",
        "asOf": "2026-09-30"
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "birth": "1990-06-15",
        "asOf": "2026-09-30"
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "birth": "1990-06-15",
        "asOf": "2026-09-30"
      }
    }
  ],
  "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 age calculator work?",
      "a": "Counts your exact age accounting for leap years, plus the countdown to your next birthday and total days lived. The underlying maths is: Age = whole years, months, and days elapsed since the birth date."
    },
    {
      "q": "What do I need to enter?",
      "a": "2 values: date of birth, and as of date. 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 exact age result mean?",
      "a": "It is returned as a plain value 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/days-between-dates",
    "https://www.revenuelab.fyi/toolbox/retirement-date"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Age Calculator (https://www.revenuelab.fyi/toolbox/age-calculator)"
}