TF2 Trade-Up Calculator

How expected profit and ROI are calculated

Input cost is the sum of the ten inputs’ acquisition prices. Expected value is the sum of each possible output’s probability multiplied by its eligible buy-order price. Expected profit is expected value minus input cost; ROI is expected profit divided by input cost, multiplied by 100.

Illustrative example, not a live opportunity: a 10 ref contract with two equally likely outputs worth 6 ref and 16 ref has 11 ref expected value, 1 ref expected profit, 10% ROI and a 50% chance of profit. The individual result is a 4 ref loss or a 6 ref gain—not a guaranteed 1 ref profit.

Price sources and limitations

Prices are saved market observations from the TF2 collection database. Background updates do not guarantee that a listing is still available. Use individual quote timestamps rather than the feed publication time to judge freshness.

Acquisition uses the lowest eligible backpack.tf sell listing. Liquidation uses the highest eligible backpack.tf buy order. Prices are observations, not reserved stock.

Unique and Strange inputs cannot be mixed. Both qualities use the lowest eligible exact backpack.tf sell listing for input acquisition and the highest eligible exact buy order for output liquidation. Missing sell listings remain unquoted instead of being estimated from buy orders. Steam pricing is temporarily disabled. Strange Parts and painted variants are filtered.

Key-mode fractions are displayed as refined metal using 64.33 refined per key, matching the conversion used by the price pipeline. This is the calculator’s conversion basis, not a claim about the current key market spread.

Decorated weapon and War Paint condition locks independently per contributing collection. Each supports Factory New, Minimal Wear, Field-Tested, Well-Worn and Battle Scarred. For example, six Minimal Wear inputs from collection A and four Factory New inputs from collection B create a 60% Minimal Wear pool from A and a 40% Factory New pool from B; they do not create a Factory New outcome from A. The calculator never substitutes Factory New prices for a different wear. Missing exact quotes stay unpriced. Steam price requests and background sweeps are paused.

For decorated weapons and War Paints, backpack.tf condition coverage is limited. Missing exact wear quotes remain unavailable; a Factory New price is never substituted for another wear.

Steam market links remain available for your own research. Steam login and key membership payments are unaffected.

Missing quotes are not treated as zero. If a required input or possible output is unquoted, a complete profitability estimate cannot be confirmed. Check the coverage and status labels before relying on a result.

In a mixed contract, each input contributes 10% probability to its collection. A collection’s probability is divided equally among its recorded next-rarity outputs: five inputs from collection A and five from collection B means a 50/50 collection split, regardless of how many outputs each collection contains. Single-collection contracts therefore remain equal probability per output. Simulations use a seeded Mulberry32 PRNG and are illustrative only.

This is a research simulator, not financial advice. No affiliation with Valve.