How much RAM does a Minecraft server need?

Count the players who are online at the same moment, not everyone on the whitelist. A server with 40 members of whom 8 play in the evening is an 8 player server.

Every server needs a base amount before the first player joins: the game itself, the loaded spawn area and whatever plugins or mods are installed. On top of that, each player keeps the area around them loaded, and that costs memory per player.

So twelve friends on a normal survival world come to 2 GB plus 12 divided by 4, which is 5 GB. Round up to the next size that exists, and you have a server that does not run at its limit.

We lean to the careful side of each range on purpose. A server that has a little room to spare copes with a busy evening; one that is sized exactly does not.

The same sum, filled in for five servers we see all the time. The memory column rounds up to a size you can actually pick.

Between the plans you can set the memory per GB up to 16 GB on the configure page, so a server that needs 9 GB does not have to pay for 12. Above 16 GB the steps grow with the size.

The numbers above assume the view distance Minecraft starts with, which is 10 chunks. A player keeps a square of chunks loaded around them that grows with the square of that distance.

Raising the view distance from 10 to 16 makes the player part of the sum two and a half times as heavy. If you want long views, plan the memory for it, or lower the simulation distance instead. Reduce lag on your server explains the difference between the two.

Since Minecraft 1.18 these are two settings in server.properties, and they cost different things. Both start at 10.

A server short of memory gains most from a lower view distance; a server short of processor gains most from a lower simulation distance. Lowering the simulation distance to 6 while keeping the view at 10 is a common trade on a busy Minecraft server: the world still looks wide, and fewer chunks have to be simulated.

Modpacks vary more than anything else. A pack of 50 small quality of life mods behaves almost like the normal game; a pack of 400 mods with world generation, machines and dimensions needs several gigabytes before anyone logs in.

• Look at the pack page: many authors state a minimum for the server.
• Count the mods. Under 100 is light, 100 to 250 is medium, above that is heavy.
• Packs with big automation mods (Create, Mekanism, Applied Energistics) grow over time as bases get bigger. Leave room.

Install a modpack on your server shows how to put a CurseForge or FTB pack on the server in one go.

Most plugins cost little memory. A few are known to need more, and they are worth counting separately in the sum.

• Live web maps such as BlueMap, Dynmap and squaremap use a lot of memory and processor while they render the world the first time, and again after a big exploring session.
• WorldEdit keeps every block of an edit in memory, so pasting a huge build or undoing one can take gigabytes for a moment.
• Extra worlds, such as a separate creative, resource or minigame world, each keep their own loaded area in memory, even when few players are in them.
• Pregenerating with Chunky runs fine on the normal sum, but it is best done when few players are online, because it keeps many chunks busy at once.

If your Minecraft server runs one of these, add 1 to 2 GB to the result of the sum, or watch the memory graph while the job runs and decide from there.

A Bedrock server has no Forge or Fabric and no Java plugins, so the sum is the one for the normal game. For most groups of friends 4 GB is plenty, and 8 GB carries a busy community.

A crossplay server is a Java server with Geyser inside it, and Geyser translates everything a Bedrock player sees. Count Bedrock players like everyone else in the sum and round up to the next size rather than down. Java and Bedrock crossplay explains how it works.

A network of several servers behind a proxy is a sum per server. The Velocity proxy itself needs little, 512 MB to 1 GB is common, and every server behind it, such as a lobby, a survival world and a minigame, gets its own sum. A lobby with no farms and a small world is the lightest of them. Build a Minecraft server network shows how the parts fit together.

• The console shows Can't keep up! Is the server overloaded? often, not just once at startup.
• The memory graph on the Overview tab sits against the top for long periods.
• The server crashes with OutOfMemoryError in the log.
• Chunks load in late when players fly or ride fast.

Not every lag is memory. A slow plugin or a huge farm can make a server lag with memory to spare. Reduce lag helps you tell the two apart.

1. Open the Overview tab during a busy evening and look at the memory graph over 24 hours, not at a single moment.
2. A sawtooth line that climbs and drops again is healthy: Java fills its memory and cleans it up in batches. A line that stays flat against the top while players complain is the warning sign.
3. On Paper and Purpur, type /spark health in the console. It shows the ticks per second, the time per tick, the processor and the memory in one view.
4. If the ticks drop below 20 while memory has room to spare, the cause is not RAM. Reduce lag on your Minecraft server helps you find it.

Recent versions of Paper and Purpur come with the spark profiler built in. On older versions, or on Fabric and Forge, spark is a plugin or mod you add yourself.

You do not have to get it perfect on day one. Start at the size the sum gives, watch the memory graph during a busy evening, and move up when it runs full. Your world stays as it is when the memory changes.

Want the sum done for you? The server finder asks what you run and how many play, and gives the size.

Java keeps the world, the players and the plugins in its heap, but it also needs memory outside the heap for itself: its own code, the network buffers, the threads and the bookkeeping of the clean up. On a Minecraft server that is several hundred megabytes, and more on bigger servers.

That is why the panel gives Java a heap a little below the memory of your plan. If the heap took the whole plan, the part outside it would have nowhere to go, and the system would stop the server without a crash line in the log. A server that vanishes without any error is often exactly that, on hosts that set the heap to the full amount.

Giving a Minecraft server far more heap than it uses does not help either. Java fills the room it is given before it cleans up, so you pay for memory that only holds waste, and the clean up itself can take longer. Size by the sum, not by the biggest number you can afford.