What is the reference ground roll?

The published landing ground roll at sea level, dry runway, standard temperature (ISA), zero wind, and the aircraft at maximum landing weight. Found in the aircraft POH performance tables.

What does the 1.67x multiplier represent?

The total landing distance from 50 ft above the threshold to full stop is approximately 1.67 times the ground roll alone. This accounts for the flare and the distance covered while descending from 50 ft.

Is this calculator suitable for real flight planning?

No. This tool is for simulator flight planning and learning. Real aircraft performance must be calculated from certified aircraft flight manual data and approved charts.

Performance Tool

Landing Distance Calculator

Calculate the runway length needed to safely land and stop. Accounts for wind, surface condition, altitude, temperature, and slope with a GO / NO-GO verdict.

CalculatorInteractive

Calculation mode

Aircraft

Headwind (+) / Tailwind (-)

kts

Runway Surface

Runway Available

Runway Sufficient

2,437 ft margin remaining

51% of runway used

Distances

Ground Roll1,335ft

Over 50 ft2,229ft

+ Safety2,563ft

Ground rollOver 50 ft+ SafetyAvailable

Includes 1.67x obstacle clearance + 15% safety margin. For sim reference only.

How to Use & Reference

About

Estimates the runway length needed to land and stop based on a reference ground roll from the aircraft's performance data, then applies correction factors for wind, altitude, temperature, runway surface, and slope. Results include ground roll, the 50 ft obstacle clearance distance, and a 15% safety margin.

How to Use

1Pick any aircraft in the fleet, grouped by simulator and searchable. Where reference figures are on file they load automatically; otherwise enter the approach speed and sea-level ground roll from the aircraft's own manual.
2Enter headwind in knots (positive) or tailwind (negative).
3Select the runway surface condition.
4Enter the available runway length to get a GO / NO-GO verdict.
5Switch to Advanced mode to add altitude, temperature, and slope corrections.

Tips

The reference ground roll is from sea level, dry, standard day, zero wind. All corrections multiply from that baseline.
Ice multiplies stopping distance by 3.5x. On an icy runway, a runway that is normally comfortable can become critically short.
A 10-knot tailwind adds roughly 25% to the landing distance. Most aircraft have a maximum tailwind limit of 10 kts.
High-altitude airports (e.g. KASE at 7,838 ft) add 25-30% to landing roll due to density altitude even on a standard day.
The 15% safety margin is the FAA Part 121 landing factor for dispatch. Always add it for realistic planning.

Formula

Ground rollrefRoll × alt × temp × wind × surface × slope

Alt factor+3.5% per 1,000 ft elevation

Temp factor+1% per °C above ISA

Wind factor-1.67% per kt headwind

Total distgroundRoll × 1.67 (50 ft obstacle)

+ SafetytotalDist × 1.15

For sim reference only. Always check the actual aircraft POH/QRH for certified performance data.

FAQ

What is the reference ground roll?: The published landing ground roll at sea level, dry runway, standard temperature (ISA), zero wind, and the aircraft at maximum landing weight. Found in the aircraft POH performance tables.
What does the 1.67x multiplier represent?: The total landing distance from 50 ft above the threshold to full stop is approximately 1.67 times the ground roll alone. This accounts for the flare and the distance covered while descending from 50 ft.
Is this calculator suitable for real flight planning?: No. This tool is for simulator flight planning and learning. Real aircraft performance must be calculated from certified aircraft flight manual data and approved charts.