Approach Speed Calculator

Work out approach speed instantly with clear inputs, formula shown and shareable results.

About Approach Speed Calculator

Approach speed starts from Vref, which is 1.3 times the landing configuration stall speed, scaled by the square root of the weight ratio because stall speed scales that way. The usual gust additive is half the gust increment, capped around 20 knots, and it is bled off before the flare.

Formula

Approach speed

Vref = 1.3 x Vso x sqrt(weight ratio); Vapp = Vref + gust/2

Worked example

With the default values below, Approach Speed Calculator returns Approach speed of 64.85. Change any input above and every figure here is recalculated in your browser.

Inputs used

Stall speed in landing configuration: 48 kt
Weight vs reference weight: 0.92 x
Gust increment (gust minus steady wind): 10 kt

Results

Approach speed: 64.85 kt
Vref at this weight: 59.85 kt
Gust additive applied: 5.00 kt
Threshold crossing speed: 62.35 kt

Step by step

1Values used
2Approach speed
3Approach speed= 64.85 kt
4Vref at this weight= 59.85 kt
5Gust additive applied= 5.00 kt
6Threshold crossing speed= 62.35 kt

Assumptions and limits

The result is derived only from the 3 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 2 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 add only half the gust?

It gives enough margin against a sudden loss of airspeed while limiting the extra landing distance that carrying speed costs.

Should the additive be flown all the way to touchdown?

No. Most techniques call for the additive to be reduced through the flare so touchdown happens close to Vref.