How to calculate VS rate?

So, I’m going to do LSZH-LOWI with a Q400, and my problem is how do I decide the VS rate?! Is there a formula?

I’ll be cruising at 21,000 feet. With a cruising speed of 230knts.

Flight is around 40 minutes long. Will start descend 63-73 nautical miles out.

Thanks! Lots of love!



Watch your speed there captain. Mach 0.71 is overspeeding in that aircraft. Keep your airspeed around 230 kts indicated.

Keep an eye on the arc on the map and you can adjust descent rate

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Oops sorry!


Just an advice to avoid overspeeding violations and fly realistic 🙂


When you start descent or climb, you will see a whitish line with slight curve move closer to your aircraft on the line of your fpl. This line will be able to tell the location you will reach that altitude with the Rate of Descent (ROD) and speed you’re currently going. You will be able to adjust your vertical speed rate using that arc of white line in front of your aircraft until it will reach your set altitude.


To calculate your descend rate you have to do GS X 5,for example: 300GS x 5=1500VS


Another notable step that you can use without formulas is Virtual Hub on your mobile or tablet. There is this section on the app saying TOD (which means Top of Descent), and what you will need to do is enter your Indicated Airspeed which is displayed to the left of your HUD, then your planned altitude and cruising altitude. It has made me successful in my TOD everytime ;)

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So I’m guessing this is an app? On the AppStore?

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Yes it is :)

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Correct, you can get this on the app store for free

Awesome, thanks! 😎

No problem! You sure have a lot of choices, but I suggest try all of them and see which is best for you. There is no right or wrong ;)


There is a bunch of formulae made to calculate your rate of descent in base of your speed and/or your distance to the BOD (Bottom of descend) when you are bored
Here is a great video about this:

But I normally stick to the easy part, obviously also had levels of realism to adhere:
I personally use this tools, had many factors to count and give a pretty precise output

Anyways, if you want an exceptional grade of realism counting also winds and you are an extremely realistic AvGeek, I would recommend this

Hope this helps!

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Agreed! Thanks again!


*Found a website to use, suggest to descend 73 Nm out with VS-1400.

*Downloading the App!


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That’s really helpful, I asked for VS rate though, unless the video also discusses it!

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All those tools/ formulae/ video shows how to calculate your descend rate and distance!

Just to close this topic, does it make sense to descend 67 Nm out a VS of -1300, and then use ILS to perfect it?

As you’re approaching LOWI you have to be careful with the terrain (please keep that in mind).

If you like check out these charts here:

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It depends on your speed and the airfield elevation.