# How much weight can a backpack carry?

I have been working on my character spreadsheet for carrying capacity and what they are carrying. I keep encountering little issues with this.

Such as a backpack

This leather knapsack has one large pocket that closes with a buckled strap and holds about 2 cubic feet of material. Some may have one or more smaller pockets on the sides.

So it can carry 2 cubic feet of material. I dont see anywhere where a cubic foot of space is given a weight allowance, as most objects you use tend to be listed by weight and not part of a cubic foot. So how can I tell what I can or cant carry?

According to Google, a cubic foot of water weights 62 pounds.

According to Google, a cubic foot of loose dirt is 74 pounds, and densely packed is 100 pounds.

So in the end, what should a cubic foot of space be expected to hold in terms of weight?

• The question isn't what a cubic foot of space can hold, but what a backpack can, right? I don't think this is defined and comes down to "what the group deems reasonable".
– Erik
Jul 13, 2016 at 18:34
• Note that you are reporting the wrong number for the weight of water, "One gallon of water weighs 8.3453 pounds. One cubic foot of water contains 7.48052 gallons. The weight of one cubic foot of water is 7.48052 gallons times 8.3453 pounds, which equals 62.42718356 pounds of water per cubic foot." Jul 13, 2016 at 18:43