Wingspan to Propeller ratio

Please suggest best Wingspan to Propeller ratio, in the view of best combination of speed of airplane and good flight time.

Is there a reason this ratio is important to you? It’s not typically the method I would use to size out an aircraft. Having said, that I looked back as some of my past small airplane designs and they range from 15% to 30% for this ratio.

Sir, thanks for your reply.

Large propeller has high efficiency as compare with small diameter propeller, but how large we can use, because large propeller develops the counter torque effect created by the main rotor, large propeller develops good thrust but speed of air is slow, large propeller create more gyroscopic effect as compare with small diameter propeller.

Small rotor are less efficient but speed of air is very fast. Low gyro and opposite counter force, So how small diameter we can use.

I think there is middle point range of size of propeller, where we will meet good ratio of “speed of aircraft” to “power of aircraft”.

May be some one has researched, with numbers of test with many combination, and come out at good range of propeller size at for best “speed of aircraft” to “power of aircraft” ratio,

May be some one researched a range KV according to wingspan and weight of plane, thereby optimum use of power may possible or best ratio of “speed of aircraft” to “power of aircraft” .

Sir If possible than please guide on that issue.

1 Like

It is a bit more complicated than just trying to optimize one ratio. I wonder if you might benefit from trying eCalc or MotoCalc programs to optimize your propulsion sysytem - they are both model based tools that are decent enough for most people in this type of forum:


Sir, heartily thanks for your reply.

Thanks for suggested model based program .

Really ratio of Wingspan to propeller is not complete without considering weight of model and area of Wingspan.

I also found a good web to find those all things, this is not work on model base, Here I properly understand that how motor KV, propeller size, pitch ratio effect overall efficiency according to wingspan, area of wing, weight of model.

Web link -

This is very clean web, free of cost, there results are not dependent on particular brands limitations. At the results we will find best perfect Battery (2s/3s/4s/5s/6s), Motor KV, Propeller size, Propeller Pitch ratio, propeller tip speed, flight duration, Ideal efficient speed etc.

Hear we need manually adjust combinations of battery, motor KV, pitch ratio according to our model plane Wingspan, area, weight. At the results we will find top efficient combination of flight duration and flight speed with graph.

Sir, please correct me and add if I am missing something.
I Google this topic “Wingspan to Propeller ratio” before post this topic , this is very common confused questions from many flyers like me also, but I observe no one has properly cleared this topic. So I think this discussion is end of “Wingspan to Propeller ratio”, this discussion may help to many designer to design efficient model Airplane. So please correct me or add from your side if I am missing something.

Thanks Sir.

Sir, I tested , this is really very good web for all my questions, that web need to pay very small fees to activate all options . . . Thanks for your guide.