Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Wind-adjusted glide distance
5.92
Still-air glide distance (nm)
7.41
Estimated glide groundspeed
60
Equivalent distance in statute miles
6.81
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How to use this
- 1Enter altitude above terrain (ft).
- 2Enter best glide ratio (distance:altitude).
- 3Enter best glide airspeed (kt).
- 4Enter headwind during glide (negative = tailwind) (kt).
- 5Read your wind-adjusted glide distance on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
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.
Worked example
Using the values the calculator loads with:
Inputs
- Altitude above terrain: 5000 ft
- Best glide ratio (distance:altitude): 9
- Best glide airspeed: 75 kt
- Headwind during glide (negative = tailwind): 15 kt
Results
- Wind-adjusted glide distance: 5.92
- Still-air glide distance (nm): 7.41
- Estimated glide groundspeed: 60
- Equivalent distance in statute miles: 6.81
What each field means
Inputs
- Altitude above terrain (ft)
- The altitude above terrain used in the calculation, measured in ft. Starts at 5000 ft so you have a working example on load.
- Best glide ratio (distance:altitude)
- The best glide ratio (distance:altitude) used in the calculation. Starts at 9 so you have a working example on load. Accepted range: 3–40.
- Best glide airspeed (kt)
- The best glide airspeed used in the calculation, measured in kt. Starts at 75 kt so you have a working example on load.
- Headwind during glide (negative = tailwind) (kt)
- The headwind during glide (negative = tailwind) used in the calculation, measured in kt. Starts at 15 kt so you have a working example on load. Accepted range: -40–60 kt.
Results
- Wind-adjusted glide distance
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Still-air glide distance (nm)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Estimated glide groundspeed
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Equivalent distance in statute miles
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Where do I find my aircraft's glide ratio?
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.
Why does wind matter this much for glide distance?
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.
Should I subtract a safety margin from this number?
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.
Does altitude above terrain mean field elevation or MSL?
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.
Accuracy and 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.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Glide Ratio Distance Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/glide-ratio-distance
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/glide-ratio-distance" target="_blank" rel="noopener">Glide Ratio Distance Calculator — RevenueLab</a> (2026).</p>
Source: [Glide Ratio Distance Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/glide-ratio-distance) (2026).