Not so much that it will spill out, and not so little that you have to scrape the sides for it.
I tend to have 1-2 broken down chalk blocks in my chalk bucket. But this also depends on the size of your chalk bag.
The amount of chalk in a chalk bag is a matter of personal preference and can vary among climbers. Some climbers prefer to have a generous amount of chalk in their bag, while others prefer a more minimal amount. Ultimately, the goal is to have enough chalk to keep your hands dry and provide good friction without excessive wastage.
A common practice is to fill the chalk bag about halfway to three-quarters full. This allows for enough chalk to coat your hands when you dip them in the bag, while still leaving room for the chalk to disperse and distribute evenly. It also helps prevent excessive spillage or clumps of chalk falling out of the bag.
Keep in mind that using too much chalk can lead to wastage and create a mess, while using too little may not provide adequate grip. It's a good idea to experiment with different amounts of chalk to find the quantity that works best for you and your climbing style. Over time, you'll develop a sense of how much chalk you personally prefer and can adjust accordingly.
Additionally, it's important to use chalk responsibly and be mindful of the environmental impact. Try to minimize chalk spills and avoid excessive chalk dust in the climbing area. Respect any specific regulations or guidelines regarding chalk usage in the climbing location you are in.
