Glide Distance Calculator
When the engine goes quiet, altitude becomes distance. A 9:1 glide ratio turns 5,000 feet of height above ground into about 7.4 nautical miles of still-air range, and wind stretches or shrinks that circle. This calculator gives the still-air distance, a wind-corrected ground distance and your time aloft, plus a reverse mode that derives your glide ratio from a glide you have actually flown.
Wind correction needs your best-glide airspeed from the POH (a Cessna 172 flies about 68 KIAS; most trainers are 60 to 80 knots). Use altitude above ground level, not sea level.
Results
Planning and training aid only. In flight, fly the airplane first and follow your training and your POH.
Quick Answer
From 5,000 feet above ground at a 9:1 glide ratio, the still-air glide distance is 45,000 ft, which is 7.41 NM or 8.52 SM. A 15-knot headwind at a 65-knot best-glide speed cuts that to 34,615 ft (5.70 NM) with about 6.8 minutes aloft, and the reverse mode reads a flown 45,000 ft glide that cost 5,000 ft of height as a real-world ratio of 9.00: 1.
- Quick Answer
- How to Use This Glide Distance Calculator
- The Glide Distance Formula, Including the Wind Correction
- Worked Example: 5,000 Feet, 9:1, 15-Knot Headwind
- Glide Ratios and Range per 1,000 Feet
- What Competing Glide Calculators Miss
- Frequently Asked Questions
- Add This Calculator to Your Website
- References
How to Use This Glide Distance Calculator
Pick a mode, enter your numbers, and press Calculate; the results stay hidden until you do. In Glide distance mode the only required entries are altitude above ground and glide ratio, and everything else refines the answer from there.
- Glide distance mode: enter altitude above ground (feet or meters), your POH glide ratio, and optionally a wind speed with a headwind or tailwind direction plus your best-glide speed in knots. The wind correction refuses to run without a best-glide speed, because a wind number means nothing until it is compared with how fast you fly.
- Find my ratio mode: enter a horizontal distance you genuinely glided and the altitude you lost over that same stretch, both in one unit. The tool divides the two and reports your measured ratio, which is usually lower than the book figure once turns, configuration and real air get involved.
- Read all five rows: still-air distance in your unit, the same distance in nautical and statute miles, the wind-corrected ground distance, and time aloft with the sink rate it assumes.
Scope matters here: this is an aviation glide tool, nothing else. If you need the straight-line distance between two airports for flight planning, use the air distance calculator instead, and for a general point-to-point ground measurement the distance calculator covers that separate job. Neither of those knows anything about altitude or glide ratio, and this page knows nothing about routes.
The Glide Distance Formula, Including the Wind Correction
Still-air distance is altitude multiplied by glide ratio, in one consistent unit. Wind does not change the aerodynamics; it changes groundspeed, and the correction follows from that.
- Still-air distance = Altitude (AGL) × Glide ratio (L/D). 5,000 ft × 9 = 45,000 ft.
- Sink rate = Best-glide speed × 1.68781 ÷ L/D, converting knots to feet per second. At 65 knots and 9:1 the sink rate is 12.2 ft/s as the tool rounds it (12.19 ft/s unrounded).
- Time aloft = Altitude ÷ Sink rate. 5,000 ft at 12.19 ft/s is about 6.8 minutes.
- Ground distance = Still-air distance × (1 − Wind / Best-glide speed) for a headwind, with a plus sign for a tailwind. A 15-knot headwind against a 65-knot glide gives a factor of 0.769, and 45,000 × 0.769 = 34,615 ft.
- Reverse ratio = Horizontal distance glided ÷ Altitude lost, both in the same unit.
One behaviour worth knowing before you trust the wind row: the tool applies the same guard to both directions, so a wind speed that meets or exceeds your best-glide speed is refused with a message about making no progress, even when you picked Tailwind. A 65-knot tailwind would stretch the glide in reality; the calculator simply declines to model winds that strong relative to the aircraft, in either direction.
Worked Example: 5,000 Feet, 9:1, 15-Knot Headwind
The pre-filled values are this example, so pressing Calculate reproduces every number below exactly. A trainer at 5,000 feet AGL with a 9:1 book ratio and a 65-knot best-glide speed faces a 15-knot headwind.
5,000 × 9 = 45,000 ft, or 7.41 NM.
1 − 15/65 = 0.769 against the headwind.
45,000 × 0.769 = 34,615 ft, or 5.70 NM.
Sink 12.2 ft/s gives about 6.8 minutes.
The tailwind figure comes from the same factor with a plus sign: 45,000 × (1 + 15/65) = 55,385 ft, or 9.12 NM. The spread between the two wind cases, over 20,000 ft from one 15-knot wind, is why the still-air circle on a chart should always be treated as the optimistic bound. If you are planning a route rather than a glide, the flight length calculator handles the trip-distance side of that planning.
Glide Ratios and Range per 1,000 Feet
Range per 1,000 feet of height is the fastest mental check in this topic: multiply the ratio by 1,000 and convert. The table uses the same 6,076.12 ft per nautical mile the calculator uses.
| Glide ratio | Feet per 1,000 ft lost | NM per 1,000 ft lost | Typical aircraft |
|---|---|---|---|
| 6:1 | 6,000 ft | 0.99 NM | Draggy configurations, gear and flaps out |
| 8:1 | 8,000 ft | 1.32 NM | Older or heavily loaded trainers |
| 9:1 | 9,000 ft | 1.48 NM | Typical single-engine trainer (the worked example) |
| 10:1 | 10,000 ft | 1.65 NM | Cleaner touring singles |
| 12:1 | 12,000 ft | 1.97 NM | Efficient light aircraft, motorgliders |
| 20:1 | 20,000 ft | 3.29 NM | Training gliders |
| 40:1 | 40,000 ft | 6.58 NM | Modern racing gliders |
Key takeaways
- Altitude above ground is the input that matters; sea-level altitude overstates range over high terrain.
- Wind changes ground distance, never the ratio itself, and the penalty scales with wind divided by your best-glide speed.
- Time aloft is a planning number, not a comfort: at trainer sink rates, 5,000 ft buys under 7 minutes.
- Your measured ratio from the reverse mode is the honest one to plan with, because it includes your aircraft, your configuration and your flying.
What Competing Glide Calculators Miss
Most rival tools stop at altitude times ratio, and the ones that add wind rarely show their working. The gaps below came from testing the top results for this exact search.
- Savvy Calculator offers wind inputs, but its own worked example cannot be reproduced: 5,000 ft at 10:1 with a 10-knot headwind is shown as 25,200 ft (4.2 NM), barely half the 50,000 ft still-air figure, with no best-glide speed anywhere in the example to justify the cut. A correction you cannot audit is a guess wearing a uniform.
- CalculatorsHub splits the topic across a glide-ratio page and a basic glide-distance page; the distance tool states that wind adjustments must be calculated separately, and neither page estimates time aloft or offers a reverse mode.
- FIRGELLI's glide ratio tool is the deepest rival, with a worked airport-reachability scenario and speed-to-fly discussion. Its strength is analysis, not a quick check: there is no compact still-air plus wind plus time output for the common trainer case.
- FlightDecide's descent and glide tool treats glide range as one FAQ inside a top-of-descent planner, so the glide question itself never gets a dedicated calculator.
- The gap this page fills: still-air distance, an auditable wind correction tied to your POH best-glide speed, time aloft from the matching sink rate, and a reverse mode that measures your real ratio, in one small tool with every formula printed.
Frequently Asked Questions
General aviation airplanes run about 6:1 to 10:1 depending on weight and configuration. Modern gliders achieve 30:1 to 60:1 or more. Always use your POH figure, flown at best-glide speed.
No. Wind does not change the aircraft's aerodynamics; it changes groundspeed. A headwind shortens the ground distance and a tailwind lengthens it, which is exactly what the wind correction computes.
The wind penalty is relative: ground distance scales with (1 − Wind / Best-glide speed) for a headwind, with a plus sign for a tailwind. Without your airspeed there is no honest way to apply the correction, so the tool asks for it instead of guessing.
Above ground level. Sea-level altitude overstates your range whenever the terrain below is high, which is exactly when the number matters most.
A windmilling propeller, extended gear or flaps, turns, turbulence, and flying off best-glide speed all cost distance. Treat the still-air figure as an outer bound and keep a margin.
It follows from the same ratio: sink rate equals best-glide speed divided by L/D. It assumes you hold best-glide speed all the way down in smooth air.
The math is identical: altitude times ratio. Paragliders typically run 8:1 to 11:1; enter your wing's published figure.
No. This is a planning and training aid. In flight, fly the airplane first and use your training; never troubleshoot with a web page.
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References
- Federal Aviation Administration. Airplane Flying Handbook (FAA-H-8083-3C). Accessed October 21, 2026.
- Federal Aviation Administration. Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C). Accessed October 21, 2026.
- SKYbrary (EUROCONTROL). Glide Performance. Accessed October 21, 2026.
- SKYbrary (EUROCONTROL). Emergency Landing: Guidance for Controllers. Accessed October 21, 2026.
- AOPA Air Safety Institute. Air Safety Institute courses and safety resources. Accessed October 21, 2026.
- Encyclopaedia Britannica. Airfoil. Accessed October 21, 2026.