Carry Weight

Carry Weight is a derived statistic in the SPECIAL system.

Fallout, Fallout 2 and Fallout Tactics
The player character will become slower as more weight is put on. When they reach the maximum weight, they become completely weighed down and cannot move until the weight is back under control.
 * $$\text{Initial level}=25+(\text{Strength}\times25)$$

For example, with a starting Strength of 5:
 * $$25+(5\times25)=150~\text{lbs}$$

Fallout 3 and Fallout: New Vegas
Movement speed is unaffected by one's carry weight until the weight of items carried exceeds the total carry weight, at which point one will become overencumbered and unable to run, jump, or fast travel, with the exception of the Long Haul perk in Fallout: New Vegas.
 * $$\text{Initial level}=150+(\text{Strength}\times10)$$

Example: A starting Strength of 5.
 * $$150+(5\times10)=200~\text{lbs}$$

Weight

 * Every added point of Strength increases weight limit by 10 lbs, including temporary bonuses added from chems, alcohol, and apparel.
 * The maximum initial level is capped at 250 lbs without the addition of extra perks.
 * The Strong Back perk increases the limit by 50 lbs.
 * The Burden to Bear perk can increase this limit by another 50 lbs.
 * The Hoarder trait increases the limit by 25 lbs.
 * The NCR Courier duster increases carry weight by another 25 lbs.
 * In Fallout: New Vegas, the maximum amount of weight one can carry is 400 lbs.
 * Using the console command, carry weight can be increased to a maximum of 20,106 lbs.
 * With the Long Haul perk in Fallout: New Vegas, one can still fast travel while overencumbered.

Fallout 4
Movement speed is unaffected by carry weight unless overencumbered, and one is unable to run or fast travel, but can still jump.

Game settings for carrying capacity:
 * fAVDCarryWeightBase = 200.0
 * fAVDCarryWeightMult = 10.0


 * $$\text{Carrying capacity}=\text{fAVDCarryWeightBase}+(\text{Strength}*\text{fAVDCarryWeightMult})$$

Bugs

 * As of patch 1.6, companions may occasionally arbitrarily gain a much higher carry weight than they would be capable of under any other circumstances. Triggering this can be as simple as repeatedly engaging a trade with the companion, taking items from them, ending the trade, re-initiating a trade and giving items to them until one has determined the bug has occurred or not. Their ability to accept even more items in subsequent trades appears to also be random. This applies to humanoid companions and Dogmeat.
 * Companions will pick up items when commanded to, even when overencumbered, making their carry weight essentially unlimited, so long as the items are first dropped and the companion is told to pick them up.