How Much RAM Does a Minecraft Server Need?
A small vanilla or Paper server for a handful of friends runs comfortably on about 3 to 4 GB. A plugin server with a few dozen players usually wants 6 GB or more. A modpack starts wherever its author says it does, commonly 6 GB or higher for large packs. Mojang does not publish an official server RAM requirement, so every number below is a rule of thumb that you should confirm with your own memory graph.
This guide is written for Minecraft Java Edition and was checked in November 2026 against Paper's documentation, modpack documentation and current hosting guidance, with Minecraft 26.3 as the current release.
- Vanilla or Paper for a small group: start around 3 to 4 GB. Add roughly 1 GB per 5 extra players and per 10 plugins, as one published hosting formula does.
- Modded servers: follow the modpack author's stated minimum. Large packs such as All the Mods typically need 6 GB or more.
- Lower
simulation-distanceandview-distancebefore you buy more RAM. - Never give Java all of the server's memory. Paper's docs say to leave about 1 to 1.5 GB for overhead and the operating system.
- Lag with free memory is a CPU problem. More RAM only helps when you see out-of-memory errors or the memory graph is pinned at the limit.
On this page
RAM starting points by server type
Use this as a first guess, then adjust from real usage. The player-count formula comes from one hosting provider's published guidance; the modded figures combine modpack documentation with general practice.
| Server type | Starting point | Notes |
|---|---|---|
| Vanilla or Paper, up to about 5 players | 3 to 4 GB | Hosting guidance often uses about 3 GB as a base for 1.17 and later. |
| Vanilla or Paper, 10 to 20 players | 4 to 6 GB | Add about 1 GB per 5 additional players. |
| Plugin-heavy Paper community, 20 to 50+ players | 6 to 10 GB | Add about 1 GB per 10 plugins. Paper's own Aikar's flags page recommends at least 6 to 10 GB. |
| Light modded (a few Forge, NeoForge or Fabric mods) | 4 to 6 GB | Hosting guidance often puts modded servers at 6 GB for 1.17 and later. |
| Large modpack (hundreds of mods) | The pack's stated minimum, usually 6 GB or more | The All the Mods docs list 4 GB as a floor on one page and 6 GB or more on another. Treat that as a minimum. |
What actually uses the memory
- Loaded chunks. Every player keeps an area of chunks loaded around them. That area is a square, so it grows with the square of the distance: a radius of 10 chunks is a 21 by 21 area (441 chunks) and a radius of 6 is 13 by 13 (169).
- Entities and block entities. Mob farms, item sorters, villagers and hoppers keep chunks busy and add memory pressure.
- Plugins and mods. Each one adds code and often its own data. Content mods that add dimensions, machines and large registries cost far more than a typical plugin.
- World size and exploration. A server that is explored heavily generates and loads more terrain than one players stay near.
View distance and simulation distance
In server.properties, view-distance controls how many chunks around each player are sent to them, and simulation-distance controls how many chunks around each player have entities and redstone ticking. Both default to 10 in the vanilla server and accept values from 3 to 32. Simulation distance is the more expensive one, because it runs game logic rather than just sending terrain.
If your server is stuttering, lowering these is the cheapest fix available. Dropping from 10 to 8 or 6 often costs players little and saves a lot of work. Some hosts preconfigure different defaults, so open the file on your own server before assuming.
Setting the RAM your server uses
Java takes its heap size from two flags: -Xms for the starting size and -Xmx for the maximum. Paper's docs show the pattern:
java -Xms4G -Xmx4G -jar paper.jar --nogui- On a NeoForge server, put RAM and other JVM options in
user_jvm_args.txt, which the installer creates. - On a managed panel you usually set the allocation in the panel rather than editing flags yourself.
- Paper's Aikar's flags page warns not to allocate all available memory on a shared host. Reduce the heap by about 1000 to 1500 MB below the total to leave room for Minecraft's overhead and the operating system.
A 26.x server needs Java 25. Minecraft 1.20.5 through 1.21.11 uses Java 21. A pack that targets Minecraft 1.21.1, such as All the Mods 10, uses the Java version for that release (Java 21).
Aikar's flags: still recommended?
Aikar's flags are a set of G1 garbage collector options created for Paper servers. As of this writing they remain on Paper's documentation as the recommended JVM flags for Paper, with -Xms and -Xmx set to the same value. The page is explicitly an explanation page and points to Paper's start script generator instead of asking you to copy flags by hand.
- They are written and tested for Paper. Do not assume they suit every server type or heap size.
- Paper's page says to use at least 6 to 10 GB with them and that more memory has diminishing returns.
- Check what your panel or start script already passes before adding flags yourself, because conflicting heap flags can stop the server from starting.
When more RAM doesn't help
Minecraft's main game loop runs on essentially one thread. If ticks slow down while memory has plenty of headroom, you are limited by CPU and by what is loaded, not by RAM.
- Raise RAM when the log shows
OutOfMemoryError, or the memory graph sits pinned at the limit while the server stutters. - Don't raise RAM when usage is comfortably below the limit and TPS still drops. Look at entity counts, chunk generation, redstone and plugin or mod timings instead.
- Pre-generate terrain. New chunk generation is expensive. Pre-generating a world border with a tool such as Chunky removes much of that load during play.
Hosting with ChicagoServers? The Minecraft server hosting page lists what is included, such as one-click mod and modpack installs, free server backups and SFTP file access.
Frequently asked questions
How much RAM do I need for a 10-player Minecraft server?
Roughly 4 to 6 GB for vanilla or Paper with a modest plugin list. Use your memory graph over a busy evening to confirm and adjust.
How much RAM does a modded Minecraft server need?
Whatever the modpack author states as the minimum. Large packs commonly need 6 GB or more, and a lightly modded server often runs on 4 to 6 GB.
Does more RAM reduce lag on a Minecraft server?
Only if the server is running out of memory. If memory is not maxed out, lag is usually caused by CPU load, entities, chunk generation or plugins and mods.
Should I use Aikar's flags?
Paper's documentation still lists them as recommended for Paper servers, and recommends using at least 6 to 10 GB with them. Check what your host already sets before adding them.