Landing Distance Required Calculator

Work out landing distance required instantly with clear inputs, formula shown and shareable results.

About Landing Distance Required Calculator

Landing distance is corrected for pressure altitude (about +5% per 1,000 ft), runway surface and condition, and the wind component. The factored figure applies the 1.43 (43%) safety factor used for public transport landing distance assessment, giving the runway length you actually want available.

Formula

Landing distance

LDR = chart distance x (1 + 0.05 x PA/1000) x surface factor x wind factor; factored = LDR x 1.43

Worked example

With the default values below, Landing Distance Required Calculator returns Landing distance required of 404.20. Change any input above and every figure here is recalculated in your browser.

Inputs used

Sea-level dry landing distance: 400 m
Pressure altitude: 1,500 ft
Runway surface / conditionone of Dry paved, Wet paved, Short dry grass, Contaminated / standing water: Dry paved
Headwind component: 5 kt

Results

Landing distance required: 404.20 m
Factored distance (1.43 safety factor): 578.00 m
Surface factor: 1.00 x
Wind factor: 0.940 x

Step by step

1Values used
2Landing distance
3Landing distance required= 404.20 m
4Factored distance (1.43 safety factor)= 578.00 m
5Surface factor= 1.00 x
6Wind factor= 0.940 x

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Aviation results are planning estimates only. Always verify take-off, landing, fuel, weight and balance figures against the certified Aircraft Flight Manual, current performance charts and applicable aviation regulations before flight.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Aviation results are planning estimates only. Always verify take-off, landing, fuel, weight and balance figures against the certified Aircraft Flight Manual, current performance charts and applicable aviation regulations before flight.

Frequently Asked Questions

Why multiply by 1.43?

Regulators require a margin between the demonstrated landing distance and the runway used in practice. A 43% additive margin (factor 1.43) is the widely used figure for turbine aeroplane landing distance available checks.

Does a wet runway always add 15%?

No. 15% is a typical planning increment; contaminated runways with standing water, slush or ice can easily add 60% or more and demand manufacturer data.