How Much RAM Does a Minecraft Server Need?

The short answer

There is no single number, because memory use depends on how many players are online, how far they can see, how many plugins or mods you run and how big the world has grown. As a rough starting point for a Java Edition server on Paper:

• 2 GB: a few friends, vanilla-style survival, a handful of light plugins.
• 4 GB: a small public server of about 10 to 20 players with a normal plugin set.
• 6 to 8 GB: 20 to 50 players, bigger worlds, heavier plugins such as land claims, economy and custom items.
• 10 GB and up: large networks, big modpacks, or many players spread over a huge map.

These are starting points to measure against, not promises. Use the checks in the last section to see what your own server actually needs.

What actually uses the memory

• Loaded chunks: every chunk around every player stays in memory. A higher view distance or simulation distance means many more chunks per player.
• Entities and redstone: farms, mob grinders, item frames and hoppers all add up, even when nobody is near them.
• Plugins: most are small, but map renderers, economy and land plugins, and anything that caches player data can be large.
• Modpacks: a Forge or Fabric pack with hundreds of mods commonly needs 6 to 10 GB before a single player joins.
• The operating system: leave 1 to 2 GB free for the system itself, or the machine starts swapping and everything stalls.

Set the amount with Java flags

Memory is set when you start the server with -Xms (starting size) and -Xmx (maximum size). Set both to the same number so the server does not spend time resizing the heap while players are on.

java -Xms4G -Xmx4G -jar paper.jar --nogui

Never give the server all of the machine's RAM. On a 8 GB machine, 5 to 6 GB for Minecraft is plenty.

More memory is not always better

Java cleans up unused memory in the background (garbage collection). With a huge heap and default settings, each cleanup can pause the server for a noticeable moment, which players feel as lag spikes. A server that needs 4 GB often runs smoother with 4 GB than with 16 GB.

If you have 5 GB or more, community-tested start flags such as Aikar's flags tune the garbage collector for Minecraft. Search for Aikar's flags and use the version for your heap size. Many hosts add them for you.

How to tell if you have the right amount

1. Play for a normal busy period, then run a profiler such as spark with /spark healthreport. It shows memory use, tick speed and what is slow.
2. Look at how much memory is free after garbage collection. If the heap is regularly more than 85 to 90 percent full after cleanups, add memory.
3. Check the TPS (ticks per second) with /tps. A healthy server stays at 20. If TPS drops while memory is nearly full, you are short on RAM. If TPS drops while memory is fine, the problem is something else, usually CPU or a heavy farm or plugin.
4. Add memory in small steps, such as 1 GB at a time, and measure again.

Choosing a host

When you compare hosting plans, RAM is only one number. Single-core CPU speed matters more than most people expect, because the main game loop runs on one thread. A plan with fast cores and 4 GB usually beats a slow-core plan with 8 GB. Also check that the plan lets you choose the Java version and server software, and that it includes backups.

Frequently asked questions