How much RAM does a Minecraft server need?

What do the documentation sources say?

The Minecraft Wiki and the Paper docs give the lowest-commercial-interest guidance, and they disagree because they answer different questions. Neither is Mojang's official minimum; no official Mojang server hardware figure was found.

• Minecraft Wiki (community-written): "For small servers, it is recommended that you have at least 2 GB of RAM available," and larger servers may need 4 GB (setup tutorial, 8 Nov 2026). It gives no per-player figure; its closest example is that -Xmx2G "is more than enough for a home server with 5 players on default simulation distance." It also says Minecraft servers "mostly utilize a single core."
• PaperMC docs (Paper is the server software they document): "We recommend using at least 6-10GB, no matter how few players!" and that 32 GB "will only waste your money with minimal returns" (Aikar's flags, 8 Nov 2026). The page presents these as flag recommendations for G1 garbage collection, not a hardware minimum, and it does not state its scope. Paper's own start-script example uses 4 GB (getting started).

Together they show a real gap: 2 GB is "more than enough" for five players on the wiki's example, while Paper recommends at least 6 GB whatever the player count. The sources do not reconcile it. A plausible reading is that the Paper figure is tuned for its recommended G1 flags and busier servers, but neither page says so.

What do hosts and guides publish?

Hosts publish the widest range, and all of these publishers sell hosting. This table shows each figure as reported on 8 November 2026.

Host Havoc also gives a formula: 1 GB base, plus 0.25 GB per player, 0.5 GB per 10 plugins and 1 GB per 20 mods, with an example of 20 players, 40 mods and 20 plugins totalling 9 GB. Its own table lists 6 GB for 15 to 25 modded players, so its two methods give different answers for similar servers (the inputs are not identical, since the formula counts plugins). None of these publishers states a test method, hardware or version behind its numbers. BisectHosting's allocation guide (23 Jan 2025) gives no player-based figures and advises changing the setting only when necessary.

For one vanilla group of about 10 players, the range across these sources is therefore 2 GB (the wiki's five-player example), 4-6 GB (DatHost's recommendation for 5-10 players) and 6-10 GB (Paper). Treat the spread as the finding; no single number is settled.

Does the server software change how much RAM I need?

Software changes what you can fit, but no source here gives a measured vanilla-versus-Paper-versus-Fabric memory comparison.

• Vanilla: the server jar from Mojang. The wiki lists Java 25 for 26.1 and later, Java 21 for 1.20.5 and later.
• Paper: a server that bundles spark since 1.21 and requires at least Java 25 for current versions (per the Paper docs). Its docs say much of the load comes from the single-threaded tick loop. No Paper page read states that it uses less or more memory than vanilla.
• Fabric: a mod loader. Memory use depends mostly on the mods you install, which is why Sparked Host's example lists 5 GB for 30 mods. Fabric's own player documentation checked on 8 November 2026 had no server memory guidance.

Plugins on Paper and mods on Fabric or Forge add memory, which is why modded figures run higher. For a heavy pack, see the worked example in ATM10 server RAM.

What is the difference between allocated heap and system RAM?

The allocated heap is the memory Java may use for game objects, set with -Xmx; system RAM is everything the machine or plan has. The Minecraft Wiki describes -Xmx as how much memory the server is allowed to use. The Paper docs advise leaving 1,000 to 1,500 MB between the heap and the host's RAM, with an example of about 6,500 MB on an 8 GB host, because Java and the operating system need memory beyond the heap. DatHost gives a similar rule: total RAM minus 0.5 to 1 GB for Minecraft.

So a plan sold as "8 GB" supports a heap of roughly 6.5 to 7.5 GB under those two rules. Paper's troubleshooting page adds that it is normal for Java to use the RAM it is given, so a full memory bar is not itself a problem.

Why is TPS low when I have spare RAM?

If TPS stays below 20 while memory is free, the limit usually points at the CPU's speed on one thread, not RAM. Ticks must finish in 50 ms to hold 20 TPS (spark docs; Minecraft Wiki). The Paper docs say the tick loop "uses a single thread" and recommend a CPU with high single-threaded performance; the wiki says servers mostly use a single core. More heap gives that thread no extra speed. RAM only matters if the heap is too small, which shows up as frequent long garbage collection or out-of-memory errors. MSPT and TPS explained covers how to tell the cases apart.

How do I size RAM from a spark reading?

Run the server with a realistic player group, read memory after garbage collection, and add headroom. That gives a number grounded in your own server rather than a table. The steps are this site's suggested method built from the sources cited, not a published standard.

1. Install or use spark (bundled with Paper since 1.21, according to the Paper profiling docs).
2. During a busy session, run /spark health for TPS, CPU, memory and disk, and /spark gc for garbage collection history (spark commands).
3. Note the heap in use right after collections drop it, the lowest points during busy play. That is roughly what the game holds.
4. Set -Xmx to that value plus headroom. DatHost suggests keeping 30 to 40 percent free for stability. As arithmetic: heap = in-use after collection / (1 - headroom fraction).
5. Add 1,000 to 1,500 MB for the host or plan size, per Paper.
6. Check TPS. If it is below 20 and memory is comfortable, stop adding RAM and look at the CPU, view distance and the profiler.

Repeat after adding mods or players. The server RAM calculator applies this arithmetic to your inputs, and how to benchmark your game server covers repeatable testing. For garbage collector flags, see Java flags for modded servers.

What would GameServerBench measure?

The planned protocol would run vanilla, Paper and Fabric servers with 5, 20 and 50 simulated players and log heap after collection and MSPT from spark. It has not been run, so no figures are given. More guides are listed in the guides index.