Arma Reforger Hosting Calculator
Estimate the RAM, CPU, and disk a modded Reforger server needs, sized from your real modpack rather than from a mod count. Every figure is broken down into the components that produced it, so you can see why.
How many players the server carries and how demanding the mission is. Empty slots cost far less than connected players, so the two are separate inputs.
Leave this at the slot count to plan for a full server.
Only used when no modpack is loaded. Load one for exact byte-based sizing.
Disk options log retention & backups
Optional, but it is what makes the estimate specific: with a real mod list the model uses actual Workshop package bytes instead of a per-mod average.
These are reforgermods.net's own planning estimates, not measurements published by any vendor. Mission scripting, AI counts, view distance, headless clients, and provider CPU contention all change real usage.
How the RAM figure is calculated
Memory is a sum of five components: a fixed baseline for an idle unmodded server, a per-player cost scaled by scenario weight, a smaller reservation for each advertised-but-empty slot, a resident fraction of the modpack's byte size, and a small per-mod overhead for registration and script binding. A safety margin is applied, then the result is rounded up to the next purchasable tier.
How the storage figure is calculated
Storage starts from the resolved byte size of your modpack, adds the server build and its base content, and adds headroom for the download peak, where a new version lands before the old one is removed. Mods whose size could not be resolved are reported separately rather than guessed at.
Why size beats mod count
A hundred small tweaks and three large terrain packs are not the same load, so a mod count cannot predict either memory or disk. Every figure here is driven by resolved package bytes and your player count instead. Tunable constants live in one calibration table and are returned with every result; those marked provisional are reasoned starting points not yet validated against measurements.
Estimates, not vendor specifications
The result is a planning estimate. It tells you the class of machine to aim for, not a guaranteed configuration, and it does not model your specific mission scripts. The same calculation is available as POST /v2/tools/hosting-estimate; feed it a real modpack from the Storage Planner.
Frequently asked questions
Are hosting estimates exact?
No. They are reforgermods.net's own planning estimates, not measurements published by any vendor. The calibration constants behind each figure are listed with the result and marked provisional until they have been validated against measured servers.
Why does it ask for my modpack instead of a mod count?
Disk and memory follow a modpack's bytes, not the number of entries in a list. Ten large terrains need far more than fifty small tweaks. Loading a real modpack replaces the per-mod average with exact Workshop package sizes, and the result says which of the two was used.
Why is CPU reported as a class rather than a clock speed?
The server's simulation loop is the bottleneck and does not spread across cores, so single-thread performance matters more than a core count. Quoting a specific GHz figure would imply a precision the model does not have, so it reports the performance class to aim for instead.
What matters most for a modded Reforger server?
High-clock CPU, adequate RAM, NVMe storage, DDoS protection, backups, file access, and clear upgrade options matter more than advertised slot count alone.