Takeoff Distance Calculator
Estimate takeoff ground roll and distance to clear a 50 ft obstacle, corrected for altitude, temperature, weight, wind, slope, and surface type.
About this calculator
Every POH takeoff distance chart is built for one set of conditions — sea level, standard temperature, max gross weight, no wind — so this calculator starts from that base ground roll and applies a stack of multiplicative correction factors for how your actual departure differs. Altitude adds roughly 10% per 1,000 ft of pressure altitude, and temperature above the ISA standard for that altitude adds another 10% per 10°C, both reflecting thinner air and reduced engine/propeller performance. Weight is corrected as the square of the ratio between your actual gross weight and the POH's reference weight, since kinetic energy (and therefore the distance needed to reach it) scales with the square of speed, and heavier aircraft need higher liftoff speeds.
Headwind trims distance at 10% per 9 kt (floored at half the no-wind distance so the model doesn't predict an unrealistic near-zero roll), while tailwind — which POHs generally limit to about 10 kt — adds distance far faster, at 10% per 2 kt (more than four times the rate of headwind's benefit), reflecting how quickly a tailwind erodes the margin against effective stopping/climb performance. Runway slope and grass surfaces (dry or wet) add further flat percentage penalties. The distance to clear a 50-ft obstacle is estimated as 1.5 times the ground roll, and the same 1.5× figure is offered again as a suggested safety margin for personal minimums — so treat that final number as a floor, not a target, and always confirm against actual runway length available.
Inputs
C172S: 960 ft, C182T: 795 ft, PA-28-181: 870 ft
Results
Takeoff Ground Roll
1,800 ft
≈ 6 football fields
Distance to Clear 50 ft
2,700 ft
≈ 9 football fields
How to Use This Calculator
- Look up the base takeoff ground roll from your POH at sea level, standard temp.
- Enter current pressure altitude, temperature, and wind.
- Enter your actual gross weight from the Weight & Balance calculator.
- The result must be less than available runway length. Apply a safety margin.
How the result changes across these scenarios
| Scenario | Takeoff Ground Roll | Distance to Clear 50 ft |
|---|---|---|
| Sea Level Standard | 907 ft | 1,360 ft |
| Hot & High (Denver) | 1,983 ft | 2,975 ft |
| Short Grass Strip | 1,737 ft | 2,606 ft |
What each input means
- POH Base Ground Roll
- Ground roll at sea level, standard temp, max gross, no wind from your POH.
- Pressure Altitude
- Use the Pressure Altitude calculator or set altimeter to 29.92.
- Outside Air Temperature
- Current OAT at the airport.
- Headwind Component
- Headwind component along the runway. Use the Crosswind calculator to determine.
- Tailwind Component
- Tailwind component. Most POHs limit tailwind to 10 kt for takeoff.
- Gross Weight
- Actual takeoff weight. Use the Weight & Balance calculator.
- POH Reference Weight
- Max gross weight the POH base distance is charted at.
- Runway Slope (uphill)
- Positive = uphill takeoff. Most runways are 0–2%. Found in Chart Supplement.
- Runway Surface
- Grass adds ~20–30% to takeoff distance.
What each result means
- Takeoff Ground Roll
- Estimated distance to liftoff.
- Distance to Clear 50 ft
- Approximate total distance including climb to 50 ft AGL.
- With 50% Safety Margin
- Many flight instructors recommend having 150% of calculated distance available.
How this is calculated
Worked example, using the default values
- Base Takeoff Ground RollFrom POH at sea level, standard temp, max gross, no wind960 ft = 960 ft
- Altitude CorrectionFactor = 1 + 10% per 1,000 ft PA1 + 0.10 × (5,000 ÷ 1000) = ×1.50
- Temperature CorrectionFactor = 1 + 10% per 10°C above ISA1 + 0.10 × (25.0 ÷ 10) = ×1.25
- Weight CorrectionFactor = (Actual Weight ÷ Reference Weight)²(2,550 ÷ 2,550)² = ×1.00
- Wind CorrectionNo windCalm = ×1.00
- Corrected Takeoff Ground RollBase × All Factors960 × 1.50 × 1.25 × 1.00 × 1.00 × 1.00 × 1.0 = 1,800 ft
Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does a tailwind hurt takeoff distance so much more than a headwind of the same speed helps?
The calculator adds 10% distance per 2 kt of tailwind but removes only 10% per 9 kt of headwind — more than four times the rate — because ground speed at liftoff, and the kinetic energy that goes with it, rises much faster with a tailwind component than it falls with an equivalent headwind. It's also why most POHs cap tailwind takeoffs around 10 kt.
Why is the weight correction squared instead of a straight-line adjustment?
Takeoff distance is corrected as (actual weight ÷ reference weight)² because kinetic energy at liftoff scales with the square of speed, and a heavier aircraft needs a higher liftoff speed to generate enough lift. A modest weight increase therefore produces a disproportionately larger increase in required distance.
What's the difference between ground roll, the 50-ft obstacle distance, and the safety margin figure?
Ground roll is the corrected distance to lift off; the 50-ft obstacle distance multiplies that by 1.5 to estimate the distance needed to also climb over a 50-ft obstacle; and the safety-margin figure applies that same 1.5× factor again as a suggested personal-minimums buffer. All three numbers come from the identical base ground roll, just scaled for different planning purposes.
Does the grass-runway surface setting account for a wet paved runway too?
No — the surface-type input only distinguishes paved, dry grass, or wet grass, adding roughly 20% for dry grass and 30% for wet grass versus paved. It doesn't have a separate option for wet pavement, so if your runway is paved but wet, treat the calculator's estimate as optimistic and add your own margin.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Density Altitude Calculator
Calculate density altitude for flight performance planning.
Aviation & Pilot ToolsCrosswind Component Calculator
Break wind into headwind and crosswind for any runway.
Flight PlanningPerformance Takeoff Calculator
Takeoff ground roll and total distance corrected for density altitude, weight, wind, and gradient.
Aviation & Pilot ToolsLanding Distance Calculator
Corrected landing distance for real-world conditions.
Flight PlanningPerformance Landing Calculator
Landing ground roll and total distance corrected for density altitude, weight, wind, and runway condition.
More in Aviation, Marine & Transport.