A32x Performance Calculator

Heer is a good Performance Calculotor for the A320 Familie.

1 Like

Yeah, I used this tool to calculate my default performance values accordingly. Then I just record that value and use the same one every time. Hahaha.

Hi the website is now appearing offline.
Does anyone know any other online calculators?


The website is online again.

1 Like

It’s for the ceo not the neo version.


https://fstools.tech - only CFM version, but online and working. Plan to add NEO variants soon.


Nice. How is CI considered?


Ah thanks very interesting read. I probably falsly assumed that Flex Temp (in your take-off calc) would be a function of CI, but now after reading, I would assume that the N1% is a function of both Flex Temp (from your take-off calc) and the CI (airline operations dependent)? Could you please comment (correct me)? thx

From what I understand and oversimplifying things, FLX Temp is you telling the aircraft which engine thrust performance that you want the aircraft to give as if the assumed outside temperature is whichever FLX Temp that you set. It calculates the appropriate take off thrust which is generally not full power to conserve the engine from wearing too quickly.

Cost Index however is just used to calculate how the aircraft will perform for the whole flight. A lower CI number would tell the aircraft to conserve fuel over everything else, that means the aircraft is generally perform with a lower performance and climb to the higher altitude as quickly as possible to gain the advantage of thinner air, thus lower drag, thus you can make do with a lower engine thrust. The drawback is that you fly at a slower pace to conserve fuel.

Higher CI means you don’t really care about fuel costs, as long as you want the aircraft to get to your destination faster. This usually means the aircraft will climb slower because it prioritises of covering the most ground distance as possible, while flying with a higher thrust consuming more fuel, but you’re flying very close to the mach limit. Essentially making you fly as fast as possible to get to your destination as quickly as possible while disregarding fuel consumption.

1 Like

Thanks that is also my understanding. I thought CI governs Flex in such a way that lower CI (less fuel consumption, less thrust) also leads to Flex being set higher - apparently I was mistaken and the two are
independent and both are considered by the FMS to set thrust.

Yeah, FLX is for Take Off thrust. and CI is for Climb and Cruise thrust.


Exactly what Neo said. CI has nothing to do with the actual performance data outputted from this calculator. Everything else though, like runway condition, temperature, etc. do play a part and basically the program takes all that into account and uses a mix of real world charts to find V-Speeds along with flex temperature.