system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are inches of rain calculated? Is it inches per square foot?
gpt
grab a glass and set it outside when it rains. When you collect it, the height you see is the height of rain reported. So long as your container maintains the same surface area the whole way down (Doesn't get wider or smaller), then it will be correct.