World size

World size refers to the size of a Terraria world. Upon creation, on the  PC version,  Console version,  Old-gen console version,  Mobile version,  Old Chinese version,  tModLoader version, and  tModLoader 1.3-Legacy version, the player can select either "small", "medium", or "large" for the size of the world to generate. On the  Windows Phone version and Nintendo 3DS version, the player can select either "normal" or "expanded". The worlds are smaller due to less memory. A "expanded" world is the equivalent of a "small" world.

Dimensions of the different map sizes are as follows: (one tile = two feet)

World	Size of map (feet)	Size of map (tiles)	Accessible area (feet)	Accessible area (tiles)	Map area (feet²)	Map area (tiles²)
Normal Tiny	3500 × 1800	1750 × 900	3486 × 1786	1743 × 893	6,300,000	1,575,000
Small Expanded	8400 × 2400	4200 × 1200	8234 × 2234	4117 × 1117	20,160,000	5,040,000
Medium	12800 × 3600	6400 × 1800	12634 × 3434	6317 × 1717	46,080,000	11,520,000
Large	16800 × 4800	8400 × 2400	16634 × 4634	8317 × 2317	80,640,000	20,160,000

World generation limits

World size has a notable impact on how many of a certain structure may be generated in the world. The values listed below are the theoretical maximums and not a guaranteed count. Although unlikely, some large structures and biomes can be skipped if no proper placement is found. Additionally, some smaller structures can be overwritten by other structures, or be blocked by other nearby structures. The ranges listed are based on chance factors during generation and not on observed data.

Placed items

Placed items

Name		World Size
		Normal Tiny	Small Expanded	Medium	Large
Life Crystals		31 Verify	100	230	403
Surface Chests		8 Verify	21	32	42
Underground Chests		n/a	35–40	80–91	140–160
Dead Man's Chests		n/a	10–20	15–30	20–40
Shadow Chests		n/a	7–10	10–15	14–20
		3–4 Verify	6–9	8–13	11–17
Statue multiplier		1 Verify	2	3	4

Treasure Rooms

Treasure Rooms

Name		World Size
		Normal Tiny	Small Expanded	Medium	Large
Floating Islands		2–5 Verify	3	5	6
Floating Lakes		n/a	1	2	3
Living Mahogany Trees		n/a	6–11	9–16	12–22
Enchanted Sword Shrines		n/a	0–1	0–3	0–4
		n/a	1	3	4
Underground Cabins		n/a	35–40	80–91	140–160
		21–22 Verify	71–74	171–176	305–311
Extra Underground Desert Cabins		n/a	2	4	8
		1 Verify	3	5	9

Mini-Biomes

Mini-Biomes

Name		World Size
		Normal Tiny	Small Expanded	Medium	Large
Bee Hives		3	6–8	8–12	11–16
Marble Caves		n/a	4–8	9–18	16–32
Granite Caves		n/a	4–8	6–12	8–16
Glowing Moss caves		n/a	2	3	4
Oasis		n/a	0-3	0-4	0-5

Abandoned Mine Tracks

Abandoned Mine Tracks

Track length		World Size
		Small	Medium	Large
Standard	Count	4–7	9–15	16–28
	Length	150–300	225–450	300–600
Extra long	Count	1–2	1–3	2–4
	Length	400–1,000	600–1,500	800–2,000
Standard	Count	10	15	20
	Length	275	287	300

World size comparison

Different world sizes may be better suited for different purposes. Players may find that creating many small worlds may be more efficient than creating large worlds due to the amount of memory needed.

Advantages of small worlds

Everything is closer and quicker to reach:

• Getting to specific locations like the Dungeon, Jungle and Oceans requires less walking.
• Building skybridges, subways, teleporters, and hellevators is quicker and less costly.
• Less digging is required to reach the Underworld.
• Floating Islands are lower and therefore easier to find.
• Wyverns spawn closer to the ground and are therefore easier to farm.
  • Note though that this can be a double-edged sword as simply being above the treetops can trigger them to spawn.
• Ores are potentially easier to find.
• The Corruption/Crimson/Hallow is easier to control.
• It is easier to find the Jungle Temple.
• Retrieving liquids such as water and lava with buckets or pumps is quicker and easier.
• Meteors are easier to locate.
• The world generates, saves, and loads faster.

Advantages of large worlds

There is more space to build and explore:

• Layer and biome transitions are more gradual.
  • The Wyvern spawn level is higher, making above-ground housing safer at low altitudes.
  • Conversely, there is more below-ground space that counts as surface, which can be used for farms of "surface-only" plants like trees or mushrooms.
• There is a greater chance of having lakes or pools big enough for fishing.
• The Underworld is longer, potentially giving more time to defeat the Wall of Flesh.
• The Celestial Towers will be more spread out, reducing the likelihood of the player's base and NPC homes being overrun.
• The evil biome or hallow is less likely to spawn near the Jungle, for the same reason as above.
• The surface terrain tends to be more varied and interesting.
• Abandoned Mine Tracks are longer and more common.

There is more "stuff" in the world:

• There are more total chests and pots underground per world.
  • This includes terrain features and structures such as Jungle Shrines, Enchanted Sword Shrines, and Floating Islands, as well as a higher chance of generating Pyramids.
• There are more materials, including ore and wood. For example, there is more wood already grown and more room to plant trees.
• The Dungeon has a greater chance to have all three Dungeon Wall types.
• There are more Evil Biome chasms. This means that there are more Shadow Orbs/Crimson Hearts to destroy, which drop unique and valuable items. There are also more Demon Altars, which means there would be more Hardmode ores to generate.
• The Jungle Temple possibly contains more traps and Lihzahrd Power Cells.
• More meteorite crash sites can be in the world at one time.
  • Like with Wyvern spawn heights, this can also be a double-edged sword as a higher number of meteorite blocks are required in the world to prevent more meteorites from spawning and potentially destroying landscapes or player built structures.

Notes

• Nintendo 3DS version values may be difficult to obtain and incorrectly extrapolated from the 1.3.0.1 source code.

Trivia

• Using server command lines with the autocreate parameter, medium sized worlds generate 6300 tiles wide instead of 6400, which is exactly 1.5x larger than small sized worlds.