CS2 Tool · Free · Offline
CS2 Trade-Up Calculator
Ten inputs, one contract — enter floats, costs and target odds to see output float, collection split and expected value first.
The three numbers that decide a contract
A trade-up contract is pure arithmetic wearing a gamble's clothes. The output float is just the average of your ten inputs — the only subtlety is clamping: if the result skin's range starts at 0.06, a 0.03 average still lands at 0.06. Collection odds are equally mechanical: six inputs from one collection mean a 60% chance the output comes from it, with the skin itself picked uniformly from that collection's items at the target rarity.
Expected value is where contracts die. Add up your ten input costs, compare against the probability weighted average of possible outputs, and most "exciting" trade-ups reveal themselves as slow losses — the house edge lives in the output pool's long tail of cheap skins. StatTrak multiplies the math: all-ST inputs keep the ST premium on the output, while a single normal input zeroes it.
This calculator takes your live Steam Market numbers instead of caching prices that rot in a day — paste current listings and get the honest EV. For settings and performance before the grind, see our CS2 settings guide and beginner guide.
Frequently asked questions
How is the output float calculated?
The output float is the average of the 10 input floats, clamped into the output skin's own float range. Ten 0.15-float inputs give a 0.15 output — then clamped if the skin's minimum is higher.
Do I need all StatTrak inputs for a StatTrak output?
Yes — the output is StatTrak only when all 10 inputs are StatTrak. Mixing even one normal input kills the StatTrak chance entirely.
How do mixed collections work?
Each input contributes 1/10 of the outcome chance to its own collection, then the skin is picked uniformly from that collection's items at the target rarity. Six inputs from collection A means a 60% chance the output comes from A.
Where do I get the prices?
From the Steam Community Market — paste the current lowest listing for each input and each possible output. Prices move daily, so this calculator takes your numbers instead of stale cached ones.
Example: single-collection contract
10 inputs, avg float 0.15, cost $12, output range 0.00–0.70. Result: output float 0.1500, collection A 100%, EV +$3.00. Verdict: "Positive EV but variance is brutal — one bad pull erases several wins."