CS2 trade-up calculator

Two contracts exist. Ten skins of one rarity return one skin of the next rarity, taken from the collections of the inputs. Since 22 October 2025, five Covert skins return one knife or pair of gloves from the case pool of one of the inputs. Five StatTrak Covert skins return a StatTrak knife; StatTrak gloves do not exist.

For the 10-skin contract, a result’s share is the number of inputs from its collection divided by 10, divided by the number of skins of the output rarity in that collection. Seven inputs from a collection with 3 results and three from one with 2 give 23.3% for each result of the first and 15% for each of the second. For the 5-Covert contract each input contributes one fifth, split across the finishes in its case pool; Valve does not publish any weighting inside a pool, so equal weights are assumed.

Each input float is first scaled inside that skin’s own float range, the scaled values are averaged, and the average is placed inside the output skin’s range. Averaging the raw floats is the most common mistake: a skin capped at 0.45 counts differently from one that runs to 1.00. Low-wear inputs cost more, and worn inputs pull every result towards Battle-Scarred.

Souvenir skins have been accepted in contracts since 22 May 2026, can be mixed with normal skins, and the output is always a normal skin. Normal and StatTrak skins cannot be mixed in one contract. This calculator covers normal and Souvenir inputs.

Skins that arrive in a Steam trade are trade-protected for 7 days and cannot go into a contract until the protection ends. The unlock calendar shows the exact time.