If you are unsure of what size bear canister you need, there are a few options. The first is to check manufacturers recommendations, as these will give you a sense of what other people are commonly able to do with it. If you can, purchase your bear canister well in advance of your trip and experiment with packing your food inside. Then, if it turns out to be too small, you'll have enough time to return it. When in doubt, try to size up, as it’s important that all your food, trash, and scented items go into your bear canister that first night.