You start with twenty inventory slots and the game gives you six more across the whole run. That is the entire story of carrying capacity, and it is why the answer to a full bag is almost never a bigger bag.
What does scale is everything around it: a belt that holds fourteen tools, bags that carry their own contents, chests that double, and a zombie who will hold fifty things for you without being asked.
Only two things make your pockets bigger
Deep Pockets is the talent, it costs a single point, and it adds five slots. It sits in the Smithing track behind Engineer and Gearmaster, which is the last place anyone looks for a carrying upgrade.
The other is a quest. Meeting the palace keeper adds one slot when it closes, and that is the whole list: twenty to start, twenty six at the absolute maximum, and no shop anywhere sells a bigger backpack.
Nothing else in the game touches the number. No building, no perk beyond Deep Pockets, no purchase and no other quest. Once you have taken the talent you are carrying as much as you ever will, so the answer to a full bag is organizing rather than expanding.
Bags carry their own space, but only for one kind of thing
Eleven bags exist and each one occupies a slot while holding nine, sixteen or twenty five of its own. The catch is that every bag accepts one family of items and refuses everything else.
A 
Tool bag takes tools and nothing but tools, a 
Farmer’s bag takes crops, seeds and fertilizer, and the specialist bags for fish, potions, food and scrolls work the same way. They cost between two hundred and fifty and a thousand coins.
The 
Big universal bag is the exception and the expensive one at five thousand. It holds sixteen and takes tools plus a general category, which is the closest the game comes to giving you more room.
A quest bag costs five hundred and holds twenty five, which is more than any other bag and more than your entire starting inventory holds after the talent. It only takes quest items, but those are exactly the things that sit in your pockets for hours because you dare not drop them.
A bag cannot go inside another bag, so stacking them is not a trick the game allows. Every bag you carry is one ordinary slot spent to gain nine, sixteen or twenty five restricted ones.
The tool belt is fourteen slots you already have
Tools do not live in your inventory at all. The belt holds fourteen and takes one of each family, so an axe, a pickaxe, a shovel, a hammer, a rod, the small kits and the rest all sit outside your pockets.
Equipping a second of the same family swaps the first back into your bag rather than adding it, so the belt fills up on its own and then stops. Carry one of each and your inventory never sees a tool again.
Storage doubles twice
A 
Simple Chest holds twenty and costs four 
Wooden Plank and four 
Bronze Nails, which is cheap enough to put several up on the first day.
A 
Chest holds thirty for four 
Oiled Plank, two Wooden Beams and six Iron Nails. A 
Large Chest holds forty for two Oiled Beams, six Carved Wood and eight Steel Screws, so the ladder runs twenty, thirty, forty as your woodworking improves.
The house comes with chests already: the one in the yard, the one indoors and the kitchen chest each hold twenty before you build anything. Most people overlook them and start building immediately.
Every zombie carries fifty items, which is more than any chest you can build and more than twice what you can hold yourself. If you are hauling something awkward across the map, the worker standing next to you is the largest container in the game.
The crafting benches are deeper still. Every conveyor bench holds ninety nine, so a mature yard has more storage sitting inside its machinery than in all of its chests put together.
Graveyard Keeper 2 inventory FAQ
How do you increase inventory size in Graveyard Keeper 2?
Two ways and no more. The Deep Pockets talent adds five slots for one talent point, and meeting the palace keeper adds one when that quest closes. You start with twenty, so twenty six is the maximum any character reaches.
Where is the Deep Pockets talent?
In the Smithing track, behind Engineer and Gearmaster, which is why nobody finds it. It costs a single talent point and is the only permanent inventory upgrade in the game.
Can you buy a bigger backpack?
No. No vendor sells inventory space. What you can buy are bags, which hold their own contents but only accept one family of items each.
What is the best bag?
The quest bag for value, at five hundred coins for twenty five slots, though it only takes quest items. The Big universal bag is the most flexible at sixteen slots, and the most expensive at five thousand.
How big are the chests?
A Simple Chest holds 20, a Chest holds 30 and a Large Chest holds 40. Your house already has three 20 slot chests before you build anything, and every conveyor bench holds 99.
Do tools take up inventory space?
No. Tools live on a separate fourteen slot belt, one per family, so an axe, a pickaxe, a shovel, a hammer and a rod all sit outside your pockets at once.
