Carry Weight

Carry Weight is a derived statistic in the SPECIAL system.

Fallout, Fallout 2 and Fallout Tactics
Your character will become slower as more weight is put on. When your character reaches the maximum weight, he or she becomes completely weighed down and cannot move until the weight is back under control.
 * $$\text{Initial level}=25+(\text{Strength}\times25)$$

Example: A starting Strength of 5.
 * $$25+(5\times25)=150~\text{lbs}$$

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

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

Fallout 4
Largely similar to Fallout 3, movement speed is unaffected by carry weight unless overencumbered, and are unable to run or fast travel. However, unlike past games, it is possible to jump.
 * $$\text{Carrying capacity}=200+(\text{Strength}*10)$$

Game settings for carrying capacity:
 * fAVDCarryWeightBase = 200
 * fAVDCarryWeightMult = 10

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.

Fallout 76
Largely similar to Fallout 4, movement speed is unaffected by carry weight unless overencumbered; you are able to run or fast travel, and can still jump. Fallout 76 differs in that running while overencumbered drains action points like sprinting. After all points are used, the character's movement will then be greatly reduced. The starting carry weight also differs because Strength starts at 1 for each player character.
 * $$\text{Carrying capacity}=155+(\text{Strength}*5)$$

Carry weight is capped to an absolute limit of 1,500 pounds over the player character's current maximum carry weight.

Backpacks
With the introduction of Wild Appalachia, player characters who complete The Order of the Tadpole are able to craft a backpack that provides +10/+20/+30/+40/+50/+60 carry weight, at levels 1/10/20/30/40/50, respectively.

One out of the five modifications for the backpack provides an extra +10/+20/+30/+40/+50/+60, totaling to +20/+40/+60/+80/+100/+120 carry weight, at the expense of -10/-20/-30/-40/-50/-60 points of energy and radiation resistance. The rest of the modifications lower the backpack's carry weight down to +5/+10/+15/+20/+25/+30, while giving other benefits.

There is a backpack that offers half the amount of a normal backpack, available at the start of the game, by crafting at the armor workbench. While it offers less than the normal one, it is nonetheless useful to increase one's carry weight, though it is recommended to acquire the normal backpack.

It provides +5/+10/+15/+20/+25/+30 carry weight, at levels 1/10/20/30/40/50, respectively.

Weight-related perks
Several perk cards assist in lightening the burden of weight, with higher tier cards reducing more:
 * Strength perks:
 * Bandolier - Ballistic weapon ammo weighs 45%/90% less.
 * Bear Arms - Heavy Guns weigh 30%/60%/90% less.
 * Martial Artist - Your melee weapons weigh 20%/40%/60% less, and you can swing them 10%/20%/30% faster.
 * Ordnance Express - Explosives weigh 30%/60%/90% less.
 * Pack Rat - The weight of all junk items is reduced by 25%/50%/75%.
 * Scattershot - Shotguns now weigh 30%/60%/90% less and you reload them 10%/20%/30% faster.
 * Strong Back - Gain +10/+20/+30/+40 to carry weight.
 * Sturdy Frame - Armor weighs 25%/50% less than normal.
 * Traveling Pharmacy - Weights of all Chems (including Stimpaks) are reduced by 30%/60%/90%.
 * Intelligence perks:
 * Batteries Included - Energy weapon ammo weighs 30%/60%/90% less.
 * Portable Power - All Power Armor parts and chassis weights are reduced by 25%/50%/75%.
 * Agility perks:
 * Packin' Light - Your pistols weigh 25%/50%/75% less.
 * Thru-hiker - Food and drink weights are reduced by 30%/60%/90%.

Strength-related perks
Not to be confused with perks cards in the Strength category, there are a couple of perk cards that affect one's total Strength, which in turn affect their carry weight:


 * Endurance perks:
 * Radicool - The greater your rads, the greater your strength! (+5 Max)
 * Solar Powered - Gain +1/+2/+3 to STR and END between the hours of 6:00 a.m. and 6:00 p.m.

Mutations
Five out of all the mutations in the game affect carry weight.


 * Marsupial adds 20 to one's carry weight, while additionally providing improved jump height. Its negative effect reduces one's Intelligence by 4.
 * Bird Bones reduces one's Strength by 4, which reduces not only carry weight, but melee damage as well. Its positive effect improves one's Agility by 4 and slows their fall.
 * Eagle Eyes reduces one's Strength by 4. Its positive effect improves one's Perception by 4 and increases critical damage by 25%.
 * Egg Head reduces one's Strength and Endurance by 3. Its positive effect improves one's Intelligence by 6.
 * Herd Mentality increases the SPECIAL stats by 2 when one is in a team, but reduces those stats by 2 when one is solo.

Legendary effects
Weapons and armor that are starred have legendary effects and, of the many effects, a few affect the weight of the starred item itself and/or other items one is carrying.


 * Weapons with 3 stars and armor with at least 2 stars may have the modifier of providing 1 Strength.
 * Weapons with 3 stars may have the minor modifier of reducing its own weight by 90%, and cannot be further reduced by any means.
 * Armor with the "Weightless" prefix reduce its own weight by 90%, and also cannot be further reduced by any means. In addition, Weightless armor does not count against the Chameleon mutation.
 * Armor with the "Unyielding" prefix adds 3 to all stats, except Endurance, when low health.
 * Armor with 3 stars may have the one of four minor modifiers that lighten the burden of weight, and these effects stack up (with perks) to a cap of 90%:
 * Ammo weight reduced by 20%.
 * Weapon weights reduced by 20%.
 * Food, drink, and chem weights reduced by 20%.
 * Junk weight reduced by 20%.

My stash box
My stash boxes share the same inventory across Appalachia, meaning that any deposited item can be withdrawn from any box, thus objects do not need to necessarily be carried across the map. The boxes can found at railroad stations, Red Rocket truck stops, or placed at any C.A.M.P. or workshop. Weight-related perks do not affect the weights of items inside it.