Backpack Route Planner
Compare a current pack with a candidate, reserve space for the outbound kit, budget loot slots, and check whether the candidate has the special storage or mobility required by the route.
Free slots
4
Slot deficit
0
Capacity change
+3
Weight reduction change
+5%
Candidate details
- Total slots
- 18
- Backpack weight
- 3
- Weight reduction
- 15%
- Shielded
- 0
- Refrigerated
- 0
- Freezer
- 0
- Warming
- 0
- Mobility
- none
Route check
The candidate covers the selected slot or mobility requirement.
- - Final carried weight is not calculated because item weight, gear, Strength, and storage placement also affect it.
Separate slot pressure from weight pressure
Abiotic Factor limits what a scientist can carry in two different ways. Inventory slots decide how many separate stacks or items fit, while carried weight determines whether movement and stamina penalties appear. A large pack can solve slot pressure without solving a poor weight plan. Conversely, a pack with a stronger weight-reduction percentage may still leave too few empty slots for the route's expected loot. This planner handles the slot question exactly and displays the pack weight and reduction values beside it so the two constraints are not mistaken for one number.
The slot calculation
Free slots equal the candidate pack's total main-inventory slots minus reserved loadout slots and planned loot slots. If the planned use exceeds capacity, free slots stop at zero and the excess is reported as a slot deficit. Capacity change compares the candidate total with the current pack total. The values listed by the Backpack article are already total main-inventory capacity, including the character's twelve starting pocket slots. The calculator therefore does not add twelve again. Doing so would overstate every backpack and make an expedition plan fail in play.
Worked example
The Basic Backpack has eighteen total slots. Reserve eight for the outbound kit and six for planned loot, and the tool reports four free slots: 18 minus 8 minus 6. Those four slots are the unassigned margin for an unexpected key item, split stack, emergency pickup, or a mistake in the packing list. If the same plan reserved fourteen slots and expected seven loot slots, it would require twenty-one slots. The result would show zero free slots and a three-slot deficit rather than displaying a confusing negative capacity.
How special-slot checks work
A radiation requirement is covered only when the candidate has at least one shielded slot. A perishable-food requirement accepts a refrigerated or freezer slot, while a frozen-item requirement needs a freezer slot specifically. Hot-food coverage requires a warming slot. Mobility is covered by a jump-boost or flight pack. This is a capability check, not a claim that one pack is best for every trip. A Research Pack can cover a radioactive item and a refrigerated item, while a Military Pack offers neither special slot even though it may be a sensible general-purpose choice at a different point in progression.
Build a recoverable outbound kit
Count every stack that must leave base before setting the loot budget. Weapons, healing, food, water, repair supplies, keys, route tools, and a return requirement each compete for space. Reserve a small unassigned margin instead of filling the candidate to its exact limit. The inventory rules matter after death because main inventory contents are placed in the player corpse while hotbar and equipped gear are handled differently. A route that uses every slot on departure may leave no capacity to recover a previous corpse or carry an unexpected progression item home.
What this planner does not calculate
The planner does not calculate exact final carried weight. That result depends on the weight and stack count of the items packed, equipped gear, Strength, temporary effects, and which inventory area holds each item. Weight reduction is shown only as a stated pack property and as a percentage-point comparison. The tool also does not estimate food decay, temperature duration, radiation accumulation, Jetpack battery range, or whether a mobility pack works in a portal world that has not been cleared. Extra backpack effects outside the modeled slots and mobility check must be reviewed separately before choosing a pack.
Source scope
Backpack totals, item weights, reduction percentages, and named special slots were checked against the community-maintained Backpack article and compared with the Armor and Gear table for game version 1.4. The Inventory article supplies the distinction between main inventory, hotbar, equipment, weight, and death-drop behavior. Entries with unresolved source conflicts or an unspecified set of special slots are omitted rather than filled with an estimate. Recheck the current item card and source table after a major game patch before replacing a progression-critical pack.
Related guides
Continue with the inventory and encumbrance guide when weight states are the problem, the special-slot guide when the route carries hazardous or temperature-sensitive items, or the portal expedition checklist to turn the slot budget into a recoverable packing plan.