What size first-aid kit do I need for camping?

Match the kit to people and days. Solo overnight or day hikes are well-served by sub-5-ounce kits in the .5 / Hiker class. Two-to-four-person weekend trips lean toward .7 or .9 / Backpacker-sized kits. Group trips of four or more people for a week or longer call for an Explorer- or Mountaineer-class kit, or a 300+ piece home/car kit kept at base camp.