How it works
The math
A tradeup contract takes 10 skins of the same rarity (and same StatTrak™ status) and produces 1 skin of the next rarity tier. The output is randomly selected from the next-rarity skins of the input collections, weighted by how many inputs came from each collection.
Float calculation
The output's float is the average of the inputs' normalized floats, mapped onto the output skin's own float range. This means using lower-float inputs of the right collection can land you in a higher wear tier, which directly affects price.
Expected Value
For each possible output, EV contribution = price × probability. We sum across all outcomes, then subtract a 13% marketplace fee to get Net EV. Profit = Net EV − input cost. ROI = profit / cost.
Prices
The dataset currently uses seeded estimates. Connecting your CSFloat API key swaps these for live market prices. Note: float-tier prices vary in real markets — the calculator uses a wear-tier average, not float-specific pricing.
Disclaimer
EV is statistical. A single tradeup with positive EV can still lose money. Profit is realized over many runs. Tradeups carry risk; never trade items you can't afford to lose.