{
  "slug": "glide-ratio-distance",
  "title": "Glide Ratio Distance Calculator",
  "heading": "Best Glide Distance Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/glide-ratio-distance",
  "summary": "How far you can glide from a given altitude after engine failure.",
  "description": "Knowing your realistic glide distance at altitude is core engine-out decision-making — it determines whether a field, road, or airport is actually within reach versus just visually close. This calculator uses your airplane's best glide ratio (distance traveled per unit of altitude lost, typically 8:1 to 10:1 for training singles, higher for gliders) combined with usable altitude above the terrain and a wind correction, since a headwind on the glide meaningfully shortens the ground distance you can actually cover.",
  "formula": "Still-air glide distance = altitude above terrain (ft) ÷ 5280 × glide ratio. Wind-adjusted distance = still-air distance × (groundspeed ÷ best glide airspeed).",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=glide-ratio-distance",
  "inputs": [
    {
      "id": "altitude",
      "label": "Altitude above terrain",
      "kind": "number",
      "hint": null,
      "default": 5000,
      "unit": "ft",
      "min": 100,
      "max": null
    },
    {
      "id": "glideRatio",
      "label": "Best glide ratio (distance:altitude)",
      "kind": "number",
      "hint": null,
      "default": 9,
      "unit": null,
      "min": 3,
      "max": 40
    },
    {
      "id": "bestGlideSpeed",
      "label": "Best glide airspeed",
      "kind": "number",
      "hint": null,
      "default": 75,
      "unit": "kt",
      "min": 20,
      "max": null
    },
    {
      "id": "windComponent",
      "label": "Headwind during glide (negative = tailwind)",
      "kind": "number",
      "hint": null,
      "default": 15,
      "unit": "kt",
      "min": -40,
      "max": 60
    }
  ],
  "outputs": [
    {
      "id": "windAdjustedDistanceNm",
      "label": "Wind-adjusted glide distance",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "stillAirDistanceNm",
      "label": "Still-air glide distance (nm)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "groundspeed",
      "label": "Estimated glide groundspeed",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "radiusMiles",
      "label": "Equivalent distance in statute miles",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Altitude above terrain: 5000 ft",
      "Best glide ratio (distance:altitude): 9",
      "Best glide airspeed: 75 kt",
      "Headwind during glide (negative = tailwind): 15 kt"
    ],
    "outputs": [
      "Wind-adjusted glide distance: 5.92",
      "Still-air glide distance (nm): 7.41",
      "Estimated glide groundspeed: 60",
      "Equivalent distance in statute miles: 6.81"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter altitude above terrain (ft).",
      "Enter best glide ratio (distance:altitude).",
      "Enter best glide airspeed (kt).",
      "Enter headwind during glide (negative = tailwind) (kt).",
      "Read your wind-adjusted glide distance 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": {
        "altitude": 3000,
        "glideRatio": 5.3999999999999995,
        "bestGlideSpeed": 45,
        "windComponent": 9
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "altitude": 5000,
        "glideRatio": 9,
        "bestGlideSpeed": 75,
        "windComponent": 15
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "altitude": 8000,
        "glideRatio": 14.4,
        "bestGlideSpeed": 120,
        "windComponent": 24
      }
    }
  ],
  "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": "Where do I find my aircraft's glide ratio?",
      "a": "It's in the POH performance section, often stated directly (e.g. 'glide ratio 9:1 at best glide speed of 68 KIAS') or derivable from the glide distance chart. If it's not published, a rough estimate for most training singles is 8:1 to 10:1; higher-performance gliders and some motorgliders exceed 30:1 or 40:1."
    },
    {
      "q": "Why does wind matter this much for glide distance?",
      "a": "Unlike powered cruise where you have excess thrust to partially compensate, in a glide you're trading altitude for distance at a fixed ratio, so a 15-knot headwind against a 75-knot best glide speed cuts your groundspeed by 20%, which directly cuts ground distance covered by the same 20% since time aloft (determined by sink rate) doesn't change."
    },
    {
      "q": "Should I subtract a safety margin from this number?",
      "a": "Yes — most instructors recommend planning to a point noticeably short of the calculated maximum glide distance, since real-world factors (turns to align with a landing spot, not holding exact best-glide speed, terrain not perfectly flat) all eat into the theoretical number. Treat this as a maximum-possible distance, not a comfortable planning distance."
    },
    {
      "q": "Does altitude above terrain mean field elevation or MSL?",
      "a": "It means height above the terrain you'd actually be landing on, not raw MSL altitude. If you're at 6,000 ft MSL over terrain at 2,000 ft MSL, your usable glide altitude is 4,000 ft, not 6,000 — always subtract the elevation of your intended landing area from your current MSL altitude first."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/fuel-endurance-range",
    "https://www.revenuelab.fyi/toolbox/climb-performance-fuel"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Glide Ratio Distance Calculator (https://www.revenuelab.fyi/toolbox/glide-ratio-distance)"
}