About TradeUp Academy

How we calculate prices and odds

Prices

For each skin and wear we collect prices from up to nine marketplaces: Steam, Buff163, Skinport, DMarket, Market.CSGO, SkinBaron, Waxpeer, HaloSkins and Tradeit. Skin pages show each marketplace’s normal and StatTrak™ price for every wear and mark the lowest. Trade-up tools use the lowest price from every marketplace except Tradeit; the trade up calculator prices Doppler results by phase. The investment calculator uses the DMarket price by default and can switch to Steam or the lowest third-party price. We do not subtract seller fees unless a tool says so.

Trade up odds

Valve does not publish trade up odds. Our calculator gives each collection a share of the result equal to its share of the inputs and splits that share evenly between the collection’s skins one rarity higher. In a five-Covert contract every possible knife or pair of gloves gets the same chance.

Doppler phases

Our calculator splits a Doppler finish’s chance between its phases by community estimates: Phase 1–4 23.75% each, Ruby and Sapphire 2% each, Black Pearl 1%. Gamma Doppler: Phase 1–4 24.75% each, Emerald 1%.

Output float

Our calculator places each input inside its float range — (float − min) ÷ (max − min) — averages those positions and maps the average into the float range of each possible result.

Wear boundaries

Valve’s Weapon Finishes Guide lists Field-Tested as 0.15–0.37 and Battle-Scarred as 0.44–1.00. Our tools use 0.07, 0.15, 0.38 and 0.45 as the boundaries between Factory New, Minimal Wear, Field-Tested, Well-Worn and Battle-Scarred.

Market cap index

The index tracks the value of CS2 items over time. We set it to $3.6 billion on 14 June 2026. Through 5 July 2026 it follows the Steam price history of a basket of popular items in six categories: knives, weapon skins, gloves, cases, stickers and agents. Since then it follows our daily total of price × active Steam listings for every priced item. Category lines split the $3.6 billion by each item’s price × its estimated copies. The estimate is the larger of its listings across marketplaces or its daily Steam sales × a typical holding period.

Expected value

The expected value (EV) of a contract is the sum of each result’s price times its chance. Compare it with the cost of the inputs.

Case ROI

Our case ROI tool uses the drop odds that Perfect World, the official operator of CS:GO in China, published for keyed cases in 2017: 79.92% Mil-Spec, 15.98% Restricted, 3.20% Classified, 0.64% Covert and 0.26% for the special item (a knife or gloves), with every item of a rarity equally likely. Wears are weighted 3% Factory New, 24% Minimal Wear, 33% Field-Tested, 24% Well-Worn and 16% Battle-Scarred, and a drop counts as StatTrak™ one time in ten where both prices exist. Opening cost is the case price plus a key at $2.49, or less if our price data has a lower key price; drops are priced before selling fees.

Steam Support: Trade Up ContractsValve: Weapon Finishes GuidePerfect World: case odds (2017)

Who writes the guides and how we earn

TradeUp Academy writes its guides with AI assistance. Game mechanics come from Valve’s announcements and Steam Support; prices and odds come from the site’s own tools. Every guide shows the date it was last edited.

Some links to marketplaces and case-opening sites are affiliate or referral links: TradeUp Academy can earn a commission when you sign up, deposit or trade through them. A partner code does not change the prices our tools show.