Many factors affect how big a plant gets, but generally speaking, if you are growing a healthy plant, you can expect these yields from one weed plant:
Outdoor plant: ½ pound of buds, or about 224g
Indoor plant: ¼ pound of buds, or about 112g
Note that these are estimates. When growing outdoors, plants can usually get massive because they aren’t restricted to space—it’s not uncommon to get closer to a pound a plant or more.
When growing indoors, you’re often limited by space—a plant can’t get as big in a grow tent as in a big, open basement. You’re also limited by how powerful your grow light is. For example, Leafly editor David Downs harvested 150g from one indoor plant with one 200W Black Dog LED light. The company said that light maxes out around a half-pound of buds, or 224g.
Also, these estimates are for healthy plants. If a plant becomes nutrient-deficient, gets bugs or mold, or doesn’t receive enough light, expect a lot less.