The wiki's baseline, and what it is not
The Terraria Wiki's requirements line for the dedicated server is one sentence: it asks for about 500 megabytes of free memory for a small world, and the same line notes that the need "depends on world size and number of players" (Server). That is the whole official baseline — one figure, scoped to the smallest world size, with the two levers named. The rest of the requirements list is software, not machine size: .NET Framework 4.0 and the XNA Framework (Server), both covered by our Terraria dedicated server setup guide.
Two things that line is not. It is not a whole-machine budget: the figure is what the server program itself wants free, and the computer underneath also runs an operating system and whatever else lives on it. And it is not a promise of headroom — the wiki scopes it to a small world and says the amount moves, which is why the rest of this page is about the levers rather than a second number.
What raises what the server holds
The wiki names the two levers itself — world size and number of players — and a third arrives with mods.
World size. The server holds the entire world in memory for as long as it runs. The three sizes a server can create are small, medium and large — autocreate values 1, 2 and 3 in serverconfig.txt — and they differ by a lot: a small world is 4200 by 1200 tiles, a medium one 6400 by 1800, and a large one 8400 by 2400, four times a small world's tile count (World size). The baseline figure is scoped to the smallest of the three, and the wiki's World size page makes the same point from the other direction: players "may find that creating many small worlds may be more efficient than creating large worlds due to the amount of memory needed" (World size).
Player count. Every connected player is state the server tracks alongside the world. The maxplayers setting caps how many — a value between 1 and 255, defaulting to 16 (8 before 1.4.0.1) — so the default server has room to grow well past the quiet friends' world the baseline suits (Server).
And one lever that points the other way: an empty vanilla server is close to its floor. "When no players are online the server hibernates. Time only passes when players are connected" (Server), and the 1.4.5.7 hotfix of August 19, 2026 went further — "Empty servers now only start updating when a client fully connects" (1.4.5.7 changelog). A reading taken at idle tells you the floor, not the working number.
How to measure your own server
The honest number for your server is the one you measure on it, with your world size, your player count and your mod list. Both desktop platforms give you a way without installing anything.
On Windows, open Task Manager while the server is running, find TerrariaServer.exe among the processes, and read its memory column. Watch it over an evening with players connected rather than at idle, for the hibernation reason above.
On Linux, ps reports it from the terminal. Its rss column is, in the manual's words, the "resident set size, the non-swapped physical memory that a task has used (in kibibytes)" (ps(1) manual) — the part of the machine's memory the server actually holds. Select the process by name and read the column:
ps -o pid,rss,comm -C TerrariaServer
The figure is in kibibytes, so divide by 1024 to put it beside megabyte numbers. Take the reading while the world is busy — players on, a large world, mods loaded — because that is the number you plan around.
What you are watching for is the server outgrowing the machine. When a process wants more than the machine has spare, the operating system starts moving things to disk to cope, and everything on the box slows down, the server included. On a computer that also runs the game client, a browser and voice chat, that point arrives sooner than the baseline alone suggests; the levers that move it are the ones above.
Why modded servers differ
A modded server is not the vanilla program with a switch flipped. tModLoader, the modding port, loads every enabled mod into the server process itself: mods ship as .tmod files, the ones to install are listed in install.txt, and enabled.json decides what loads at startup (tModLoader wiki). A content mod's items, enemies and systems become state the server holds and work it does, on top of the vanilla world.
So the baseline does not transfer. A tModLoader server's need is the vanilla server's plus whatever its particular mod list costs — two small utility mods and a large content overhaul are different servers for this purpose — and the only honest figure is one measured on the mod list you actually run. The version gap matters too: tModLoader's own server guide carries the note that it "runs on an older version of terraria" than the current release (tModLoader wiki), so a modded server is not simply today's vanilla server with mods added. TShock, the other common distribution, is built on the vanilla server and adds its own account and plugin system (TShock releases); the same rule applies — measure the setup you run, not the label on it.
What this means if you rent instead
Renting moves the server onto someone else's machine; it does not change what the program needs. The questions that set the number are the same — which world size, how many players, vanilla or modded — and they are the right questions to ask any host. This site describes its own plans by player slots rather than machine figures, so this page carries no ForgeWorld numbers: it is the neutral explainer, and the plan detail lives on the Terraria availability page.
If you would rather have a server that stays online without running it yourself, ForgeWorld Gaming’s Terraria plan is Terraria Standard, 4 player slots, CA$8.99/month; the availability page shows whether orders are currently open. Other sizes and tiers are not available yet. Your server is set up automatically after payment. Current plans and prices are on the Terraria availability page.