Rust Decay Calculator

Rust Decay Calculator

Estimate when a Rust base part will start decaying, how long it takes to break, and how soon you should refill the Tool Cupboard.

Plan decay around material tier, health, and TC protection

A Rust decay calculator estimates how long a base, wall, door, or deployable takes to decay in Rust. Decay time depends on building material, upkeep status, and Tool Cupboard coverage. Stone walls decay slower than twig structures, while armored structures can last for days when upkeep remains stocked.

Choose the material tier, enter the current health percentage, and add any Tool Cupboard protection time left to calculate decay start time, remaining decay time, and total time from now.

This page improves on a basic material-and-health timer by including TC protection, custom server decay speed, a check-in forecast, exposed-piece warnings, and a decay timeline. That makes it more useful for checking whether a base can survive until the next login.

Default values use common Rust decay times for twig, wood, stone, sheet metal, and armored building tiers. Modded servers can change decay behavior, so use the advanced settings when your server runs custom rates.

The building tier that is losing upkeep.

Enter current HP as a percentage from 0 to 100.

Hours before upkeep runs out. Use 0 if decay has started.

Advanced server and planning settings Open for modded servers

1 is default, 2 is twice as fast, 0.5 is half speed.

Optional hours from 100% to 0%. Use 0 for default.

Forecast HP when you plan to log back in.

Optional count for planning notes.

Decay remaining

Full decay time x current HP %

Total time

TC time + remaining decay time

Server speed

Higher speed shortens decay time

How to use the Rust decay calculator

  1. Choose the material tier: Select twig, wood, stone, sheet metal, or armored for the part that may decay.
  2. Enter current health: Use the remaining HP percentage. A half-damaged wall should be entered as 50%.
  3. Add TC protection time: Enter how many hours the Tool Cupboard says the base is protected. Use 0 when the needed upkeep material has already run out.
  4. Open advanced settings only when needed: Use custom full decay or speed settings for modded servers, and add a check-in time to see whether the base should still be standing when you return.
  5. Read the total timer: The result combines the time before decay begins and the remaining decay time after upkeep is gone.

Rust decay formula

Rust decay time can be estimated by treating health loss as linear after upkeep is gone. If a stone wall takes 5 hours to decay from 100% health to 0%, then a stone wall at 50% health has about 2.5 hours of decay left after the TC stops protecting it.

Remaining decay = full decay time x current health percent

Total time from now = TC protection left + remaining decay

Effective full decay = full decay time / server decay speed

Example: a stone part at 75% health with 6 hours of TC protection left has about 3.75 hours of decay after upkeep ends, so the total estimated time until destruction is 9.75 hours on a default server.

Decay and Tool Cupboard reference: Facepunch Rust Wiki - Tool Cupboard, decay and building privilege.

Rust building decay times by material

Material tier matters because each building material has a different full decay duration once the matching upkeep resource is gone. Use this table for quick estimates, then use the calculator when the part is already damaged or the TC still has protection time left.

Material Full decay time Upkeep resource Best use for the calculator
Twig 1 hour Wood Temporary raid or build pieces that disappear quickly.
Wood 3 hours Wood Early bases, doors, and vulnerable starter structures.
Stone 5 hours Stone Common main-base shells and honeycomb layers.
Sheet metal 8 hours Metal fragments Core rooms, garage doors, and stronger exposed pieces.
Armored 12 hours High quality metal Small high-value cores and bunker pieces.

Tool Cupboard upkeep and mixed-material bases

A mixed base can run out of one upkeep material while other tiers remain protected. For example, if a base has stone walls and sheet metal doors but the TC runs out of stone only, the stone parts can begin decaying while the metal parts remain protected by metal fragments.

Check each resource

Look at wood, stone, metal fragments, and high quality metal separately instead of assuming the whole base has the same timer.

Protect the TC room

If the Tool Cupboard is raided or emptied, the timer shifts from upkeep planning to decay survival.

Watch disconnected externals

Separate structures need their own protection. Do not assume an external wall or detached base piece is covered.

Server setting reference: Facepunch Rust Wiki - Useful console commands.

Decay planning scenarios

The same decay number means different things depending on when you can return, whether the part is exposed, and whether the base is still protected by the TC. Use these scenarios to interpret the calculator result.

Scenario What to enter How to read the result
TC still has upkeep Enter the TC protection time shown in game. The total timer includes the protected period plus decay after resources run out.
Upkeep already empty Set TC protection to 0 and enter the current health percent. The remaining decay time is the practical countdown from now.
Modded server Open advanced settings and change decay speed or custom full decay time. Use the result as a server-specific estimate instead of a vanilla estimate.
Checking before next login Enter your planned check-in time in the advanced settings. The forecast shows whether the piece should remain protected, damaged, or destroyed.

Base upkeep checklist

A decay timer is most useful when it becomes a practical checklist. Before logging off, check the TC, disconnected structures, external walls, and any tier that uses a scarce material.

Before logging off

Confirm every needed upkeep resource has enough time, especially stone for honeycomb and metal fragments for doors.

After a raid

Check whether the TC survived, whether grief protection consumed upkeep, and which exposed pieces are already losing health.

For external TCs

Treat every detached external as its own structure with its own refill schedule.

For teams

Use the shortest resource timer as the shared reminder so teammates do not assume someone else already stocked the base.

Building terminology reference: Facepunch Rust Wiki - Building terminology.

Frequently Asked Questions

What is a Rust decay calculator?

A Rust decay calculator estimates how much time a base part has before it reaches 0 health after upkeep runs out. It can be used for a wall, foundation, ceiling, floor, door, or other protected structure as long as you choose the closest material tier. This calculator also includes Tool Cupboard protection time, current HP percentage, server decay speed, and a check-in forecast so you can plan around your next login instead of only seeing a simple timer.

How do I calculate decay time in Rust?

Choose the building material, find its full decay time, multiply by the current health percentage, then add any Tool Cupboard protection time left. The resource that matters depends on the tier: wood upkeep protects wood pieces, stone protects stone pieces, metal fragments protect sheet metal, and high quality metal protects armor-tier structures. For example, stone has a 5-hour full decay time on the default setting. At 60% health with 2 hours of protection left, the estimate is 2 + (5 x 0.60), or 5 hours total from now.

When does Rust decay start?

Decay starts when the relevant upkeep resource is missing from the Tool Cupboard inventory or when the structure is outside TC coverage. If only one material runs out, only pieces that need that material may begin to lose health, which is why a raid or poor maintenance can damage one layer while another stays protected. Separate buildings, detached externals, and modded server rules can also change what is protected.

How long does stone take to decay in Rust?

Stone takes about 5 hours to decay from full health after there is no stone upkeep available on a default server. The same estimate can apply to a stone wall, foundation, floor, or ceiling because the calculator is based on material health rather than the visual part name. If the stone part is already damaged, multiply 5 hours by the current HP percentage. A stone wall at 40% health has about 2 hours of decay left once protection is gone.

Does the Tool Cupboard stop all decay?

A Tool Cupboard stops decay only for the connected building or protected structure and only while the needed upkeep materials are available in its inventory. It does not automatically protect every separate base, external, detached structure, or raid-damaged door nearby. Check each TC timer, each upkeep resource, and each material tier before relying on the result.

Why does my server decay at a different speed?

Rust servers can use custom decay, upkeep, maintenance, and protection settings, and community servers may run plugins that change the normal timer. Use the advanced decay speed or custom full decay field when your server is not using vanilla behavior. A speed of 2 cuts the effective decay time in half, while 0.5 doubles it, which can make a base decay much faster or slower than expected.

Other useful calculators

Stone Weight Calculator

Estimate stone weight from volume and density.

Pipe Weight Calculator

Calculate pipe weight by diameter, thickness, length, and material.

Glass Weight Calculator

Estimate glass panel weight from dimensions and glass type.

Container Loading Calculator

Estimate boxes, pallets, and cartons per container.

Retaining Wall Calculator

Estimate blocks, caps, gravel, fabric, and base material.

Rolling Offset Calculator

Find pipe travel, offset, rise, run, and fitting angles.

Disclaimer: This Rust decay calculator is for general game planning and informational use only. It estimates timing from user-entered material tier, health percentage, Tool Cupboard protection time, full decay time, and server decay speed. It does not read your Rust server, confirm your TC inventory, account for every plugin or admin setting, guarantee vanilla behavior, calculate exact upkeep cost, detect disconnected structures, model exposed outer-layer decay order, include raid damage, or replace in-game checks. Rust updates, community server modifications, custom decay rules, grief protection settings, and building layout can change the actual result. Always verify timers in game before logging off or making important base decisions.

Last updated: June 6, 2026