It really depends on the chin and what kind of wood and chews are on the toys. I have several chew toys hanging in each cage, and when the wood on them gets low, like when I can see the wire or chain a reasonable amount, I add more wood/chews to the toy. Some things last longer, others last shorter amounts of time. For example, I have some thin pine blocks that I use, which are chewed in no time, but the 1" thick alphabet cubes last awhile. Anything willow/grapevine that I add to the toys also is chewed quickly, but some thicker pieces of grapevine are still lasting me after a few years. I do swap what toys are in what cage every so often so the chins get a variety.