Work out the output rarity, outcome odds and resulting float before you commit ten skins. Every number is calculated client-side and the formulas are shown in the open.
Choose your input rarity, split ten inputs across up to two collections, set the average float, and read the odds and estimated float for each possible outcome.
A trade-up always takes 10 inputs of one rarity and returns a single skin one tier higher. Split those 10 inputs across up to two collections below.
| From | Per-collection odds | Per-skin odds | Est. float | Wear |
|---|---|---|---|---|
| Set your inputs above to see the odds. | ||||
Educational tool only. No skins are traded, no money changes hands, and nothing here connects to your account until you choose to sign in with Steam.
How this works: Outcome odds use the standard trade-up model — each input buys one entry into the collection draw, then the result is spread evenly across that collection's next tier. Estimated float uses Valve's published formula (output = min + averageInput × (max − min)). Pool values are community estimates and shift constantly, so treat them as guidance.
The 10-input rule, the six rarity tiers, and how the contract picks your output collection and outcome odds.
What float means, the five wear brackets, and how the average float of your inputs sets your output float.
How to judge a contract with expected value, why most trade-ups lose money, and when the maths can favour you.
Why every input belongs to a collection, how that decides your possible outputs, and how mixing two collections changes the odds.
Why all ten inputs must be StatTrak, why the output always stays StatTrak, the separate output pool, and the kill-counter reset.
Each output skin's own min and max float, why the cap can block Factory New, and a worked example of the float formula.
Select the rarity of the ten skins you plan to trade up (Consumer through Classified).
Set how many of the ten inputs come from each collection — the totals must add up to ten.
Enter the average float of your inputs to estimate the float of the skin you would receive.
Read your outcome odds, then sign in with Steam to line up the exact skins from your inventory.
Exactly ten skins, and all ten must share the same rarity. You cannot use nine, eleven, or mix rarities within a single contract.
You always receive one skin from the rarity directly above your inputs — ten Mil-Spec inputs return a Restricted, ten Classified return a Covert. Covert is the ceiling, so there is no trade-up beyond it.
The contract averages the float of your ten inputs and maps it onto the output skin's own range with the formula output = min + averageInput × (max − min). Low-float inputs pull your reward toward cleaner, usually more valuable conditions.
Not exactly. You choose the collections your inputs come from, and each input adds one entry to the draw, so loading more inputs from one collection raises the chance the result comes from it. The specific skin within that tier is then random.
Usually not. Community estimates suggest most casually assembled trade-ups come out negative once marketplace fees are counted, though exact figures vary by collection. A contract only makes sense when its expected value comfortably clears the cost of the inputs plus fees.
Yes, it is completely free with no sign-up, and it involves no real money or gambling. It is an informational tool that shows outcome rarity, odds and estimated float so you can plan a contract before committing skins in-game.
Save your setups, connect with other players, and explore more. Sign up free with Steam.