Rust Decay Calculator 2026: TC Upkeep, Time-to-Decay, Per-Tier Costs

Rust’s Tool Cupboard upkeep system is the difference between a base that survives the week and a base you respawn next to. Most groups understand the basics: TC empty, base decays. But the actual numbers, how much stone per day, how many minutes of farming to keep a 6×6 alive, when you should switch from stone to metal, are widely guessed and rarely calculated. This calculator is the calculation.

How TC upkeep actually works

The Tool Cupboard pulls building materials from its inventory at a steady rate per 24 hours. Each piece of your base, foundations, walls, doorways, windows, roofs, stairs, has its own per-piece daily cost. Pieces drain from the TC as long as the inventory has the right material in it. Once the TC runs empty for a given material, those pieces start taking decay damage and eventually destruct.

Two things to know up front:

• Foundations cost more than walls per piece. A stone foundation costs 8 stone/day, a stone wall costs 5 stone/day. A naive count of “wall surface area” undercounts your real upkeep.
• Bigger bases pay a higher rate per piece. Upkeep is a tax on what each piece cost to build, and that tax rate climbs with the number of connected building blocks, through server-defined brackets that run from roughly 10% to 33%. It is applied in bands rather than all at once: on a 20-block structure the first 15 blocks may be taxed at 10% and the next 5 at 15%, giving about 11.3% overall. So doubling your block count more than doubles your bill. Note this is driven by block count, not by how far a piece sits from the cupboard – distance from the TC does not change what a piece costs.

Per-tier upkeep at a glance

The biggest sticker-shock for new players is comparing tiers. Here’s the per-piece daily cost across the four real combat tiers:

• Wood: Foundations 5 wood, Walls 3 wood. Cheap to feed but soaks 1 satchel charge to break.
• Stone: Foundations 8 stone, Walls 5 stone. The standard solo/duo tier. Requires real raid effort to break (1 explosive ammo door, 4-6 rockets per wall section).
• Sheet metal: Foundations 16 metal frags, Walls 10 metal frags. Roughly 2x stone upkeep but significantly tougher to raid.
• Armored (HQM): Foundations 3 HQM, Walls 2 HQM. Drains HQM (your scarcest resource), but 1 wall takes 4-5 rockets to break. Worth it for high-value loot.

Real upkeep examples

Concrete base sizes and what they cost in the calculator’s defaults:

Solo 2×2 stone base: 4 foundations + 8 walls + 1 doorway + 4 roofs = roughly 80-100 stone/day. A single boulder in the desert biome yields ~100 stone, so 1 boulder per day keeps the base alive.

Duo bunker (sheet metal): 6 foundations + 14 walls + 2 doorways + 1 window + 6 roofs = roughly 350-400 metal frags/day. A single metal ore node gives ~50 frags after smelting, so 7-8 nodes per day. Realistic for an active duo.

Small clan base (HQM exterior): 16 foundations + 40 walls + 6 doorways + 4 windows + 16 roofs = roughly 230-280 HQM/day. HQM is hard to farm; 1 ore node gives ~5 HQM, so 50+ nodes per day. This is why clans burn workhours on HQM trips.

When to upgrade tier

The decision tree most groups follow:

1. Twig/wood: only as construction stage. Never your final tier. Wood walls die to a hatchet.
2. Stone: default solo/duo tier. Sheet metal isn’t worth the upkeep cost for a base that nobody serious is raiding.
3. Sheet metal: when you have items worth raiding for (medium-value loot, working farm, high tier workbench). Sheet metal walls force the raider to commit explosive ammo.
4. Armored (HQM): when you’re a target. Clan bases, end-of-wipe stockpile bases, anything with M249s and rockets stored. The upkeep cost is real but raider cost is higher.

If your TC empties

Decay damage starts almost immediately when the material runs out, and this is the part people get badly wrong: these timers run in hours, not days. Time-to-destruction by tier, in the default server config, straight from Facepunch’s own Tool Cupboard documentation:

• Twig: 1 hour (intentional anti-griefing).
• Wood: 3 hours.
• Stone: 5 hours.
• Sheet metal: 8 hours.
• Armored: 12 hours.

Read that against your own play schedule. A stone base whose TC runs dry after you log off is gone before you get back the next evening, and even an armored base does not survive a full day unattended. This is why the upkeep number matters more than any raid-cost number: almost nobody loses a base to explosives while offline, and a great many people lose one to an empty cupboard.

One useful piece of mercy in the mechanic: if your TC is destroyed while it still has resources in it, it consumes up to 24 hours of upkeep on the way out, so the base holds for about a day afterwards rather than starting to decay immediately.

The calculator above flags the weakest tier in your base, since that’s the one that fails first. A mostly-armored base with one stone wall on the back fails when that one stone wall decays in 5 hours. Mixed-tier bases inherit the weakest tier’s timer for the affected pieces.

Server-side overrides

Vanilla Rust uses the rates above. Modded and community servers often tune them:

• 2x decay servers: halve the time-to-decay numbers. Good for fast-wipe scrim servers.
• No-decay servers: you keep your base forever as long as TC has any material. Good for build-experiment or roleplay servers.
• 0.5x upkeep: daily cost halved. Common on beginner-friendly community servers.

If you run a custom server, the relevant config keys are decay.scale and decay.upkeep_period_minutes. Both are exposed in our panel for our managed Rust servers.

Strategies to lower your upkeep

Three patterns that actually save resources:

Fewer blocks. A 2×2 base with 8 wall pieces costs less than a 4×4 with 32 walls, and the gap is wider than the 4x block difference suggests: the larger block count also drags you into a higher tax bracket, so the 4×4 costs more than four times what the 2×2 does. The biggest single lever is how many building blocks you place – not how they are arranged, and not how far they sit from the cupboard.

Decoy walls and bunkers. A small inner armored core with a sacrificial outer stone shell halves your HQM cost compared to a fully-armored exterior. Raiders waste boom on the stone shell; the core stays cheap.

Don’t overbuild for storage. A second TC plus an extension to hold loot doubles your upkeep. Storage in a single compact base is cheaper than a base with annexed storage rooms.

Hosting a Rust server

Most Rust groups eventually rent a private server when their public-server experience gets too messy. Our managed Rust hosting handles oxide / Carbon plugin install, scheduled wipes, ddos protection, and panel-based config (decay rate, upkeep multiplier, BP wipes, etc) so you don’t need to touch a config file. Pricing scales with map size and player slots.

For raid math (the offensive side of base management), our companion Rust Raid Calculator covers the sulfur, explosive ammo, and time costs to break each wall tier. It pairs naturally with this one: raiders use the raid calc, defenders use the decay calc.

Bottom line

Decide your tier based on what you’re protecting, not what you can afford to farm. Stone is fine for solo loot. Sheet metal is right for serious base content. Armored is for when you’re a target and the upkeep cost is worth the raider cost. The calculator gives you the daily numbers; the strategy is yours.