How CS2 Trade Up Contracts Work — A Calculator Guide
Trade up contracts are one of the few mechanics in CS2 where you can consistently turn lower-value weapon skins into higher-tier items. The catch is that the outcome is probabilistic — you need to understand the math before committing real money. This calculator lets you build any contract, set exact float values, and see every possible outcome with its probability and profit before you execute it in-game. Below is everything you need to know to use it effectively.
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
CS2 Trade Up Calculator — Frequently Asked Questions
Click the empty skin slots to search and add weapon skins. Once you've added all 10 inputs of the same rarity (or 5 for Covert), the calculator instantly shows every possible outcome with its probability, sell price, and profit. You can also set custom float values on each input to see how wear conditions affect the output.
RTP stands for Return to Player. It's the average percentage of your input cost you get back as output value. An RTP of 120% means you can expect $1.20 back for every $1.00 spent on average. Contracts with RTP above 100% are considered profitable over time, though individual results will vary due to the random nature of trade ups.
The output skin's float is derived from the fitted average of your 10 input floats, mapped to the output skin's float range. Lower input floats push the output toward Factory New or Minimal Wear conditions, which are almost always worth more. Use the custom float editor in the calculator to experiment — even a 0.01 difference can shift the output to a better wear bracket and significantly increase its market value.
Yes. Every contract gets a unique shareable URL that encodes the skins and float values. Click the "Share" button on a completed contract to copy the link or share directly to Twitter, Reddit, Facebook, or WhatsApp. Anyone who opens the link sees the exact same contract with live market prices.
The profit simulation runs your completed contract 10 to 100 times and charts the cumulative profit over each attempt. It's a Monte Carlo simulation that shows how the contract performs across many tries, helping you understand variance. A contract with high RTP but low profit chance might need 50+ executions to turn green — the simulation makes that visible.
Time Travel recalculates a contract using historical skin prices from any past date. This lets you see how a CS2 trade up contract's profitability has changed over time. It's useful for spotting seasonal price patterns and understanding whether a contract that looks profitable today was always good or is specific to current market conditions.
The calculator lets you manually build a specific CS2 trade up contract and analyze its outcomes in detail. The simulator uses a genetic algorithm to automatically discover the most profitable contracts from all available skins. Use the simulator to find good contracts, then open them in the calculator to fine-tune floats, explore edge cases, and run profit simulations.
Yes. Skin prices are based on current market data and update regularly. When you add a skin to the calculator, the buy price shown reflects recent market rates. This means profit calculations and RTP are based on what you'd actually pay today, not outdated averages. For historical analysis, use the Time Travel feature to see prices from any past date.