For me I’d say approximately 18 bananas.
Here cost of 2.5 Kg bananas = cost 1 Kg chicken .
1 Kg bananas = 5 each ( average 200 gms weight)
So approx 12 bananas and a half (small banana)
Is the chicken dead or alive? And is it free-range?
Converting the letters to numbers 1.6061 bananas = 1 chicken.
I don’t really care for bananas, so it would have to a lot. 50 or 60, maybe? I don’t know, it needs to be enough so that I could easily sell them at such a price that I could afford to buy a new chicken and have a small profit left over, but do I really want to pester my friends and neighbors to buy cheap bananas? No, I don’t, and especially not since they’d ask why I have a surplus of unwanted bananas, and I’d have to explain about the whole trading a chicken for bananas thing, which isn’t going to make any damn sense to them, and their opinion of me would undoubtedly take a hit.
So I don’t know, the answer may be infinity bananas.
You can have all my bananas for a living chicken. I want eggs and hate bananas. I’ll take a fancy bantam chicken.
If I’m in a climate where bananas can grow, I bet I have a neighbor who wouldn’t miss one or two. Chickens are much harder to come by. So… somewhere around thirty thousand pounds. More if they come pre-mashed.
Occasionally I read news items about people buying bananas and finding a spider lurking in the bunch. If you are lucky the spider will bite you and the supermarket will offer compensation for your traumatic experience.
So, I give you a chicken and you give me a bunch of six bananas with a non-poisonous spider contained therein. Plus, I’ll need a receipt from the place you bought them from. One guy received £200 from Tesco in this way but I reckon I could hold out for £500, minimum.
I don’t want your chicken unless it’s cooked.
If you can turn it into some nice Kievs, I’ll give you as many bananas as you like.
Personally, I’m currently on a low-carb diet and can’t have bananas at all. So any exchange ratio would be acceptable.
As an exercise in economics, it depends mainly on how cheaply and easily I can get bananas, and how hard chickens are to come by. If I have a grove of banana trees that supply me with more bananas than I can eat, while the chicken I trade for is the ONLY source of protein in my diet, then I would be willing to trade a heck of a lot of bananas for one chicken. It also depends on how badly the guy with the chicken wants to trade. If he hates bananas, I’m out of luck.
Of course on the other hand, my mom tells me about the time one of my dad’s moonshining brothers bought up a load of surplus bananas and made hootch out of them. The result was something like strongly banana-flavored brandy. That might be a “value-added” product I could try. 
I figure a chicken is approximately two meals so it would be worth two meals of bananas but you would also get use out of the bone and feathers so that is probably equivalent to a third meals of bananas. Now the question is how many bananas is a meal? I would figure about 8.
So 24 bananas equals a dead chicken.
If it is an alive egg producer it would probably add another 12 bananas.
That’s pretty darn close. A banana can be had in many places for about $.20. The last chicken I bought was a touch over $4.00, maybe $4.50.
I’m vegetarian, so I can’t eat the chicken. (Well, more accurately, *won’t *eat the chicken.) The banana-to-chicken ratio thus depends on whether I’m exchanging the chicken for the banana, or vice versa. If I’ve got my hands on the chicken, even one banana will get me to part with it. However, if you’ve got a chicken you’re trying to sell me, I’m not going to give you any bananas at all in exchange.
I suppose this averages out to 0.5 banana per chicken.
How many banannas would I trade for a chicken?
Zero.
Have you ever had a chicken daquarie?
Like Shot From Guns, I’m a strict vegetarian, so even one banana is more useful to me than a chicken. (Unless, of course, this is a companion chicken to which I am sentimentally attached, in which case no quantity of bananas would induce me to part with it. Given the intelligence and demeanor of the average chicken, however, I consider the likelihood of such an attachment ever forming to be quite low. If you show me a clever and charming chicken I will show you an animal whom I will quite readily consider a friend and potential accomplice, but until such a thing can be shown to exist such speculation is quite bootless.)
Of course, my prospective chicken purchaser might not know this, so I would probably hold out for a more reasonable exchange, which would naturally depend on supply and demand. Let’s say at least a dozen bananas – a substantial windfall for me, but low enough to significantly undercut any non-vegetarians trying to exchange their chickens for bananas, thus most likely expediting the sale of my chicken. If chicken supply is quite high, on the other hand, or if there are other vegetarians likewise attempting to liquidate their chicken assets and willing to undercut even my reasonable offer, I may be forced to accept a lower price.
On the other side of the mercantile coin, I might offer up some of my banana holdings in the interest of one or more chickens only if circumstances are propitious to a speedy and profitable turnaround. Perhaps Shot From Guns is willing to part with her chickens for one banana each, but isn’t aware that VarlosZ has a banana surplus and a chicken deficit and is offering the princely sum of sixty bananas for a single chicken. In this case the temporary possession of a chicken is very useful to me, despite my unwillingness to make a snack out of it. But if the chicken market is saturated, I’ll just keep my bananas, thanks.
Hit it, Big John!
Stealth Potato, I was considering only the OP’s question, which is how much is it worth to me. Clearly, if other mercatile opportunities were to present themselves, this would have a considerable impact on the landscape. The banana-chicken landscape.
I hereby move that we portmanteau banana-chicken into banicken for the remainder of this thread.
Well, I think it’s all interconnected. The banicken market landscape (band name!) might have a considerable impact on how much a chicken is worth to you. In my example, for instance, each of your chickens is worth about 59 bananas to me. 
Is the chicken alive and capable of laying? A dead chicken would be worthless to me as I/we don’t eat dead chickens. Whereas my daughter goes through a LOT of bananas and eggs and would LOVE to have a pet chicken:). Whatever the market will bear, I guess. 
Nanars are pretty cheap…we could strike a deal.
I don’t like bananas. Would your hypothetical chicken seller accept peaches?
I don’t think we want to start confusing chickeach transactions with banicken ones. That would just be ridiculous.