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CS2 Trade-Up Guide

CS2 Trade-Up Probability Calculator — Outcome Odds

Understanding probability is the difference between gambling and trading in CS2. Every trade-up outcome has a calculable probability based on the input collections. Learn how to calculate and manipulate these odds in your favor.

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All TiersInput Rarity
All TiersOutput Rarity
Probability-weightedTypical ROI Range
VariesTypical Cost

How Trade-Up Probabilities Are Calculated

Each trade-up output has a specific probability determined by two factors:

  1. Collection weight: How many of your 10 inputs come from each collection
  2. Skins per collection: How many possible output skins exist in each collection at the target rarity

Formula:

P(skin) = (inputs_from_collection / 10) × (1 / skins_at_target_rarity_in_collection)

Example: 6 inputs from Collection A (which has 4 Restricted outputs) → each Collection A Restricted skin has probability: 6/10 × 1/4 = 15%

Manipulating Probabilities in Your Favor

You can weight probabilities by choosing how many inputs come from each collection:

  • Load toward valuable collections: 7–8 inputs from the collection with the best outputs
  • Use filler from cheap collections: 2–3 inputs from collections with cheap skins (even if their outputs are mediocre)
  • Avoid dilution: Collections with many cheap outputs at the target tier dilute your probability of the valuable skins

Key insight: A collection with 2 expensive outputs at 10% each is often better than a collection with 6 outputs where only 1 is expensive at 3.3%.

Probability vs. Profitability

High probability doesn't always mean high profit. What matters is the probability-weighted expected value:

  • A 5% chance of a €200 skin contributes €10 to EV
  • A 50% chance of a €5 skin contributes €2.50 to EV
  • The rare skin contributes MORE to profitability despite lower probability

TradeUpX calculates the full EV across all outcomes, so you don't need to do this math manually. Focus on total EV and ROI, not individual probabilities.

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Frequently Asked Questions

How is trade-up probability calculated?
Probability = (inputs from collection / 10) × (1 / output skins in that collection). Each output skin in a collection has equal probability within its share.
Can I guarantee a specific output?
Only if all 10 inputs come from one collection AND there's only one output skin at the target rarity. Otherwise, there's always randomness.
Does putting more skins from one collection increase my odds?
Yes. More inputs from a collection = higher total probability for that collection's outputs. This is how you weight the odds toward valuable skins.