You can't convert kilograms directly to stones without knowing the type of stone you're talking about. Here's why:

* Stones vary in weight: A small pebble weighs much less than a large boulder.

* "Stone" can be ambiguous: It could refer to a specific type of rock, or it could be a more general term.

To get a rough estimate, you could assume a "stone" is about 1 kilogram. In that case:

* 80 kilograms would be approximately 80 stones.

However, this is just an estimate. To get an accurate answer, you need to know the specific type of stone you are referring to.