system
Given the following post, respond as if you're commenting on Reddit:
human
When they say an inch of rain, does that mean cubic inch?
gpt
An inch of rain means that if you would catch the rain on a flat surface, it would reach up to an inch in height. To properly measure this, you need to make sure that the water can't flow away or dissipate into the ground, so you'd need a waterproof box with an open top for the rain to fall in. The amount of water it takes to reach a certain waterlevel obviously depends on the surface area of the measurement box. However, so does the amount of water entering the box via rainfall, so that evens out and ultimately it means that the size (and shape) of the measurement box is not important.

1 cubic inch of water will raise the water level in a 1 square inch box to 1 inch.