What does the trade-up calculator do?
Add the skins you plan to put into a Trade Up Contract. The calculator checks that the contract is allowed, lists every skin it can give you, the chance of each one, and the float and wear each one would have. It also adds up your cost, the expected value, your profit or loss and the chance that you come out ahead.
Every input and outcome price starts at the Skinport lowest listing for that item's exact wear and StatTrak state, from our daily price snapshot. A knife pool uses the average listing of its items. You can type over any price to use your own. Nothing is bought or sold here, and we do not add market fees. Use the Steam fee calculator if you want to take fees off your sell prices first.
What are the trade-up rules in CS2?
Valve's rules come from the Steam Support page for Trade Up Contracts and two later release notes. The links are in the source box next to the tool.
| Rule | Normal contract | Covert contract |
|---|---|---|
| Number of inputs | 10 | 5 |
| Input rarity | All the same rarity, Consumer to Classified | All Covert |
| You get | One skin of the next rarity | One knife or one pair of gloves |
| StatTrak | All StatTrak or none | 5 StatTrak Coverts give a StatTrak knife |
| Souvenir | Allowed with normal items, result is normal | Same rule |
| Where the result comes from | A collection of one of the inputs | The case of one of the inputs |
Valve added the Covert contract in the Counter-Strike 2 update of 22 October 2025. Souvenir inputs were allowed from the update of 21 May 2026. A skin that is already the top rarity of its collection cannot be traded up, and knives and gloves can never be inputs.
The Covert rule has one more limit. StatTrak gloves do not exist, so StatTrak Coverts from a case that only has gloves, like the Revolution Case, give nothing and the calculator flags them.
How are the odds of each outcome calculated?
Valve does not publish the odds method. Community guides written after the October 2025 update report that each input adds an equal share, and that share is split evenly between the next-rarity skins of its own collection.
Chance of a skin = (inputs from its collection / total inputs) x (1 / next-rarity skins in that collection)
So a collection with more inputs gets more of the odds, and a collection with fewer possible outcomes gives each outcome a bigger slice. The calculator adds up the chances when two inputs point at the same skin.
For Covert contracts, we show the chance per case, since Valve does not say how the knife or glove is picked inside a case. You enter the average value you expect from that case pool.
How is the output float calculated?
Each outcome skin has its own float range, so each outcome gets its own float. By default, the calculator uses the normalised formula that community testing reports since October 2025:
- Each input float becomes a position inside its own range: (float - min) / (max - min).
- The ten positions are averaged.
- Output float = output min + average x (output max - output min).
You can switch to the classic formula, the plain average of raw floats, to compare. See the float capping calculator to work backwards from a wear you want.
Worked example 1: two collections, ten Restricted inputs
This is the example loaded in the tool. It uses 7 Restricted inputs from The Revolution Collection and 3 from The Kilowatt Collection.
| Inputs | Float range | Floats used |
|---|---|---|
| 4 x M4A1-S | Emphorosaur-S | 0.00 to 0.80 | 0.04, 0.045, 0.05, 0.055 |
| 3 x Glock-18 | Umbral Rabbit | 0.00 to 0.75 | 0.03, 0.04, 0.06 |
| 3 x Glock-18 | Block-18 (Kilowatt) | 0.00 to 0.671875 | 0.02, 0.035, 0.05 |
Each collection has three Classified skins. Revolution gets 7 of 10 shares, so each of its three Classified skins gets 70% / 3 = 23.33%. Kilowatt gets 3 shares, so each of its skins gets 30% / 3 = 10%.
The average trade-up value is 0.056711. That gives these outputs:
| Outcome | Range | Chance | Output float | Wear | Skinport lowest listing (FN) |
|---|---|---|---|---|---|
| UMP-45 | Wild Child | 0.00 to 1.00 | 23.33% | 0.056711 | FN | $16.25 |
| P2000 | Wicked Sick | 0.00 to 1.00 | 23.33% | 0.056711 | FN | $14.27 |
| AWP | Duality | 0.00 to 0.80 | 23.33% | 0.045369 | FN | $10.02 |
| M4A1-S | Black Lotus | 0.00 to 0.70 | 10% | 0.039698 | FN | $10.26 |
| Zeus x27 | Olympus | 0.00 to 0.67 | 10% | 0.037997 | FN | $6.95 |
| USP-S | Jawbreaker | 0.00 to 1.00 | 10% | 0.056711 | FN | $16.22 |
Now the money part, with the Skinport lowest listings from our 24 Sep 2026 snapshot. The tool fills these in for you. The inputs are all Factory New: 4 Emphorosaur-S at $2.35, 3 Umbral Rabbit at $1.75 and 3 Block-18 at $1.49, so the contract costs $19.12.
The expected value is 0.2333 x (16.25 + 14.27 + 10.02) + 0.10 x (10.26 + 6.95 + 16.22) = 9.46 + 3.34 = $12.80. That is a loss of $6.32 on average, or 33% of the cost. No single outcome is worth more than $19.12, so the chance of profit is 0%. Prices change every day, so check the numbers the tool shows before you trade. Read how to calculate trade-up EV for more on why even a positive average can still lose most of the time.
Worked example 2: a StatTrak knife contract
Put 5 StatTrak Covert skins from The Kilowatt Collection in, for example StatTrak AK-47 | Inheritance at 0.05 (range 0.00 to 0.797346). All five point at the Kilowatt Case, so the case pool gets 100% of the odds. The knife in that case is the Kukri Knife.
With an average trade-up value of 0.05 / 0.797346 = 0.062708, each knife finish gets its own float:
| Knife finish | Range | Output float | Wear |
|---|---|---|---|
| Kukri Knife | Fade | 0.00 to 0.08 | 0.005017 | FN |
| Kukri Knife | Slaughter | 0.01 to 0.26 | 0.025677 | FN |
| Kukri Knife | Night Stripe | 0.06 to 0.80 | 0.106404 | MW |
| Kukri Knife | Case Hardened | 0.00 to 1.00 | 0.062708 | FN |
Here is the money side, from Skinport lowest listings on 24 Sep 2026. Five StatTrak AK-47 | Inheritance (Factory New) cost 5 x $225.31 = $1,126.55. The StatTrak Kukri outcomes were listed at $163.15 (Fade, FN), $145.25 (Slaughter, FN) and $88.14 (Night Stripe, MW). StatTrak Case Hardened in FN had no listing. The tool averages the three listed prices to $132.18, so this contract loses about $994 on average. You can type your own pool value if you expect a different result.
If you swap two of the inputs for StatTrak Coverts from The Revolution Collection, the contract becomes invalid. The Revolution Case only holds gloves, and there are no StatTrak gloves. With normal quality Coverts the same mix works: 60% Kilowatt Case pool, 40% Revolution Case gloves.
When should I use a trade-up calculator?
- Before you buy inputs, to see if a contract can make money at the prices you see.
- To check the wear of every outcome, not only the one you hope for.
- To test how a single cheaper or cleaner input changes the odds and floats.
- To check a Covert to knife contract before you give up five Coverts.
Most contracts lose money on average, because the market already prices in the odds. A calculator helps you find the rare ones that do not, and avoid the ones that only look good.
Related tools and guides
- Float capping calculator: the highest average input for a target wear.
- Float checker: the wear and position of any float.
- How trade-up contracts work
- Float capping explained
