{
  "slug": "sleep",
  "title": "Sleep Calculator",
  "heading": "Sleep Cycle Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/sleep",
  "summary": "When to sleep (or wake) to align with 90-minute cycles.",
  "description": "Sleep happens in ~90-minute cycles. This suggests bedtimes that end on a cycle boundary so you wake refreshed.",
  "formula": null,
  "dateModified": "2026-10-03",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=sleep",
  "inputs": [
    {
      "id": "wake",
      "label": "Wake time (HH:MM, 24h)",
      "kind": "text",
      "hint": null,
      "default": "07:00"
    },
    {
      "id": "fallAsleepMin",
      "label": "Mins to fall asleep",
      "kind": "number",
      "hint": null,
      "default": 14,
      "unit": null,
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "c6",
      "label": "9 hrs sleep — bed at",
      "format": "raw",
      "hint": null,
      "primary": true
    },
    {
      "id": "c5",
      "label": "7.5 hrs sleep — bed at",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "c4",
      "label": "6 hrs sleep — bed at",
      "format": "raw",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Wake time (HH:MM, 24h): 07:00",
      "Mins to fall asleep: 14"
    ],
    "outputs": [
      "9 hrs sleep — bed at: 21:46",
      "7.5 hrs sleep — bed at: 23:16",
      "6 hrs sleep — bed at: 00:46"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter wake time (hh:mm, 24h).",
      "Enter mins to fall asleep.",
      "Read your 9 hrs sleep — bed at 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": {
        "wake": "07:00",
        "fallAsleepMin": 8
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "wake": "07:00",
        "fallAsleepMin": 14
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "wake": "07:00",
        "fallAsleepMin": 22
      }
    }
  ],
  "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 sleep cycle calculator work?",
      "a": "Sleep happens in ~90-minute cycles. This suggests bedtimes that end on a cycle boundary so you wake refreshed."
    },
    {
      "q": "What do I need to enter?",
      "a": "2 values: wake time (hh:mm, 24h), and mins to fall asleep. 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 9 hrs sleep — bed at 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/time-duration"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Sleep Calculator (https://www.revenuelab.fyi/toolbox/sleep)"
}