Contract Builder

Trade-up contract rules and a live ranking of the cheapest filler skins for every rarity transition — prices update automatically.

This page is about Trade Up Contracts — a mechanic inside the game CS2: you run them in your own Steam inventory. This site does not perform trades, does not take your skins and is not affiliated with Valve — everything below is for information only.

Build a contract

Drag fillers from the grids below into the slots — or just click a card and it takes the first free slot. Enter or Escape on a slot removes the item.

Filled 0/10

Input cost $0.00

Add the first item — it sets the rarity for the whole contract.

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Clear Fill with cheapest

Consumer Grade → Industrial Grade

Best fillers

5 outputs PP-Bizon | Bizoom The Achroma Collection $0.01

5 outputs SSG 08 | Sans Comic The Achroma Collection $0.01

6 outputs Nova | Marsh Grass The Radiant Collection $0.01

6 outputs PP-Bizon | Wood Block Camo The Radiant Collection $0.01

5 outputs FAMAS | Byproduct The Harlequin Collection $0.01

5 outputs SG 553 | Safari Print The Harlequin Collection $0.01

9 outputs MAC-10 | Storm Camo The Ascent Collection $0.01

9 outputs P250 | Plum Netting The Ascent Collection $0.01

9 outputs M249 | Sage Camo The Boreal Collection $0.01

9 outputs P250 | Copper Oxide The Boreal Collection $0.01

5 outputs PP-Bizon | Thermal Currents The Harlequin Collection $0.01

9 outputs SSG 08 | Grey Smoke The Ascent Collection $0.01

Industrial Grade → Mil-Spec

Best fillers

6 outputs SG 553 | Basket Halftone The Radiant Collection $0.04

4 outputs FAMAS | Vendetta The Achroma Collection $0.04

4 outputs XM1014 | XoooM The Harlequin Collection $0.04

4 outputs MP5-SD | Neon Squeezer The Overpass 2024 Collection $0.05

4 outputs MAC-10 | Snow Splash The Achroma Collection $0.05

6 outputs FAMAS | Grey Ghost The Radiant Collection $0.05

4 outputs MP5-SD | Snow Splash The Achroma Collection $0.05

6 outputs Tec-9 | Citric Acid The Radiant Collection $0.05

5 outputs R8 Revolver | Leafhopper The Boreal Collection $0.05

5 outputs MAC-10 | Acid Hex The Boreal Collection $0.05

5 outputs Nova | Turquoise Pour The Ascent Collection $0.05

5 outputs SSG 08 | Tiger Tear The Boreal Collection $0.05

Mil-Spec → Restricted

Best fillers

5 outputs Nova | Dark Sigil The Kilowatt Collection $0.12

5 outputs MAG-7 | Foresight The Dreams & Nightmares Collection $0.12

5 outputs SCAR-20 | Poultrygeist The Dreams & Nightmares Collection $0.13

5 outputs Dual Berettas | Hideout The Kilowatt Collection $0.13

5 outputs SG 553 | Ol' Rusty The Fracture Collection $0.14

5 outputs XM1014 | Irezumi The Kilowatt Collection $0.14

5 outputs SCAR-20 | Fragments The Revolution Collection $0.14

5 outputs UMP-45 | Motorized The Kilowatt Collection $0.14

5 outputs Negev | Ultralight The Fracture Collection $0.15

5 outputs P250 | Cassette The Fracture Collection $0.17

5 outputs Galil AR | Destroyer The Recoil Collection $0.17

5 outputs XM1014 | Oxide Blaze The Clutch Collection $0.17

Restricted → Classified

Best fillers

3 outputs MAC-10 | Sakkaku The Revolution Collection $0.43

3 outputs UMP-45 | Grand Prix The Chroma 2 Collection $0.48

3 outputs USP-S | Ticket to Hell The Dreams & Nightmares Collection $0.55

3 outputs P90 | Neoqueen The Revolution Collection $0.56

3 outputs Sawed-Off | Analog Input The Kilowatt Collection $0.56

3 outputs M249 | Downtown The Recoil Collection $0.61

3 outputs P90 | Vent Rush The Recoil Collection $0.65

3 outputs SG 553 | Dragon Tech The Recoil Collection $0.68

3 outputs Negev | dev_texture The Snakebite Collection $0.69

3 outputs XM1014 | Zombie Offensive The Dreams & Nightmares Collection $0.69

3 outputs Negev | Lionfish The Clutch Collection $0.72

3 outputs Zeus x27 | Tosai The Fever Collection $0.73

Classified → Covert

Best fillers

2 outputs XM1014 | Entombed The Fracture Collection $3.97

2 outputs Zeus x27 | Olympus The Kilowatt Collection $4.39

2 outputs R8 Revolver | Skull Crusher The Prisma Collection $4.62

2 outputs P250 | Visions The Recoil Collection $4.97

2 outputs AUG | Stymphalian The Clutch Collection $5.34

2 outputs UMP-45 | Momentum The Danger Zone Collection $5.45

1 outputs M4A1-S | Solitude Limited Edition Item $5.68

2 outputs AWP | Duality The Revolution Collection $5.85

2 outputs P90 | Nostalgia The CS20 Collection $6.03

2 outputs UMP-45 | Wild Child The Revolution Collection $6.14

2 outputs XM1014 | XOXO The Snakebite Collection $6.15

2 outputs M4A1-S | Black Lotus The Kilowatt Collection $6.19

10 → 1

A contract takes exactly 10 skins of the same rarity. In return you get 1 random skin of the next rarity from the collections your inputs belong to. Each collection’s chance is proportional to how many of your inputs come from it.

Example: 7 inputs from collection A (4 outputs) and 3 from collection B (2 outputs): chance of A = 7/10 = 70%, each of its skins ≈ 70% / 4 = 17.5%; chance of B = 30%, each skin ≈ 15%.

Output float

Each input’s float is normalized within its own range: (float − min) / (max − min). The average of these values is projected into the output’s range.

n = average over 10 inputs ( (float − min) / (max − min) ) output float = out_min + n × (out_max − out_min)

Example: 10 inputs averaging n = 0.10 with an output range of 0.00–0.50 → 0 + 0.10 × 0.5 = 0.05 — nearly Factory New.

StatTrak separately

Inputs must be either all StatTrak or all non-StatTrak — no mixing. Souvenir skins are not accepted. Covert is the ceiling: knives and gloves never drop from contracts.

Example: 10 StatTrak inputs → a StatTrak output; 10 regular → a regular one. 9 regular + 1 StatTrak simply cannot be placed into a contract.

Economics

A contract is profitable when 10 × the input price is below the expected value of the output. Odds are proportional to the number of output skins in the input collections — a cheap filler from a collection with expensive outputs is what you are looking for.

Example: 10 fillers at $0.30 = $3.00 in. If the average price of possible outputs is $4.20, expected value is +$1.20; if it is $2.00, the contract loses money.

Trade Up Contracts are a mechanic inside the game CS2 (Valve). This site does not perform trades, does not take items and is not affiliated with Valve Corporation. Prices come from external marketplaces and may differ from current listings. This material is for information only and is not financial advice.