A jar of honey weighs 454grammes and a bee can carry about 0.04grammes of nectar. But nectar is only about 40% sugar and honey needs to be about 80% sugar so the bee actually only carries about 0.02grammes of honey on each trip.
Now how many bees would we need to fill a jar of honey? The answer is 454/0.02 grammes which equals =
22,700 bees are required to fill a single jar of honey.
This sounds impressive enough but of course a colony of bees doesn't just make one jar of honey. Over the year the queen will produce between 100,000 and 200,000 bees that will each spend between 10 and 20 days collecting nectar.
At its most productive a single colony of bees could theoretically produce around 800kg of honey, that's almost a tonne!
The reason that beehives aren't the size of warehouses to accommodate all this honey is that it is being continually used up by the bees as fuel, primarily to keep the brood warm. So at any given time there may only be between 10 and 20kg of honey in the hive.