The formula
honey = hives × supers × frames × kg per frame × (1 − loss)
Where it comes from
Production is estimated per frame, which is the unit beekeepers actually work in: a well-capped Langstroth frame gives around two and a half kilos. The loss figure covers what stays in the cappings, on the walls of the extractor and in the strainer, and it is bigger than it looks the first time. Bottling means going from weight to volume, and that is the trap: honey does not weigh like water. A litre is about 1.42 kilos, so a hundred kilos of honey does not fill a hundred litres but seventy, and anyone buying jars by the litre ends up with jars left over.
How to work it out by hand
- Multiply hives by supers taken and by the frames in each super
- Multiply by the kilos of honey in a frame: that is the gross crop
- Take off the loss from uncapping and straining
- Divide by 1.42 for litres, and by the jar weight for the number of jars
What is worth knowing
The density of 1.42 kg per litre is for honey at bottling moisture, around seventeen per cent. Wetter honey weighs slightly less per litre and also risks fermenting: above eighteen per cent it should not be bottled. Kilos per frame depend on hive type, on the flow and on the year, so the default is a starting point and not a forecast.