No worries, just calculate the volume you currently have and divide it by the number of days you've been collecting. Say you have a box with a width of 7 inches, a length of 11 inches, and your trash reaches a height of 8 inches after 4 days. Now convert those measurements to feet (0.583 ft by 0.916 ft by 0.666 ft) and find the volume of trash you collected. In this case it would be 0.355 cubic feet. Divide this by 4 and you create 0.0889 cubic feet of garbage per day. I hope this helps.