How CS2 Trade Up Contracts Work
A CS2 trade up contract takes 10 weapon skins of the same rarity (or 5 for Covert tier) and returns 1 skin of the next higher rarity. The output is randomly selected from the collections your inputs belong to, weighted by how many skins come from each collection.
For example, if 8 inputs are from Collection A (which has an expensive Classified skin) and 2 from Collection B, you have an 80% chance of getting the Collection A outcome. The calculator shows you these exact probabilities so you can evaluate the contract before spending anything.
- Submit 10 skins of the same rarity (5 for Covert)
- Receive 1 random skin of the next tier from shared collections
- Outcome probabilities depend on collection distribution
- StatTrak™ contracts require all StatTrak inputs
Float Values and Wear Conditions
Every CS2 skin has a float value between 0 and 1 that determines its wear condition — Factory New, Minimal Wear, Field-Tested, Well-Worn, or Battle-Scarred. The output skin's float is derived from the fitted average float of your 10 inputs, mapped onto the output skin's float range.
This calculator lets you set custom floats on each input skin. A lower average input float pushes the output toward better wear conditions, which almost always means a higher sell price. Even a small float difference can shift an output from Minimal Wear to Factory New — worth testing before you buy inputs.
- Set exact float values on each input skin
- Output float is calculated from the fitted average of all inputs
- Lower input floats = better output wear = higher value
- Use the float editor to test different scenarios
Understanding Profit, RTP, and Break-Even
Once you add all 10 skins, the calculator displays every possible outcome with its probability and profit. Three key metrics help you evaluate a CS2 trade up contract:
- RTP (Return to Player) — the percentage of your input cost you can expect back on average. Above 100% means the contract is profitable in the long run.
- Profit Chance — the probability that the outcome sells for more than your total input cost. A 70% profit chance means 7 out of 10 times you'd make money.
- Mean Profit — the average profit across all outcomes, weighted by probability. Positive mean profit is the clearest indicator of a good contract.
Profit Simulation and Historical Prices
Completed contracts unlock a profit simulation that runs the trade up 10, 25, 50, or 100 times and charts your cumulative profit over each attempt. This reveals how a contract performs across multiple tries — essential for understanding variance and expected outcomes.
The Time Travel feature lets you recalculate any contract using historical skin prices from a specific date. This is useful for tracking how a contract's profitability has changed over time and spotting weapon trading opportunities based on price trends.
- Visualize cumulative profit and individual outcomes
- Use Time Travel to see historical contract profitability
- Share contracts via URL with friends or communities