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Reverse Trade-Up Calculator

Pick the skin you want and how low its float should be. We find the cheapest ten inputs that get you there and what the contract is worth.

About the CS2 Reverse Trade-Up Calculator

Guide

How CS2 Reverse Trade-Ups Work

A reverse trade-up calculator works backwards. Instead of dropping in 10 inputs and watching the outcomes appear, you start from the outcome you actually want — a specific skin at a specific float — and the calculator solves for the inputs. It runs the same CS2 contract math the forward calculator does, just inverted, so the recipe it produces is exactly what the game will accept.

The inverse float formula

Forward, the contract normalizes each of 10 input floats against its skin's range, averages them, then maps the result onto the target skin's range. Reverse, the calculator solves the same equation for the missing piece — the per-input float:

avgNormalized = (targetFloat − targetMin) / (targetMax − targetMin)
requiredFloati = candidateMini + avgNormalized × (candidateMaxi − candidateMini)

Every candidate input gets its own required float because every skin has its own min/max range. That's also why two different inputs with the same raw float can both be valid for the same target — the contract only cares about the normalized average.

When a target float is unreachable

If avgNormalized falls outside [0, 1], the recipe is impossible — no combination of valid inputs can produce that output float. This happens when the target float you typed sits outside the target skin's actual min/max range. The calculator flags the field and waits for a float inside the valid window, so you never configure a contract the game would refuse.

Which inputs the calculator considers

Only skins one rarity tier below the target and from the target's collection are eligible — that's the contract rule. The float budget table shows every viable option, the highest float each one can have if all ten are that skin, and its cheapest live price. You don't have to use one skin: the calculator mixes skins and floats to find the ten cheapest live listings whose average still lands on your float. The outcomes table shows every other skin that could pop out of the same contract, because a trade-up always rolls the full pool, not just your chosen target.

Why It Helps

Why Use a Reverse Trade-Up Calculator?

The forward calculator is great when you already know which inputs you have. The reverse calculator is what you want when you know which skin you want to land. Picking 10 inputs by guesswork in the forward tool, watching them produce something close-but-not-quite, and re-tuning the floats by hand is slow. Solving the inverse equation in one shot is instant.

  • Outcome-first design. Start from the skin and float you want; let the math figure out the inputs. Useful when you're chasing a specific Factory New variant or a clean Minimal Wear roll.
  • Mixes inputs for the real floor. Only the average float matters, so a low-float copy can carry cheaper high-float ones. The calculator searches those mixes for the cheapest ten.
  • Real listings, real fees. The contract cost is ten live listings you can open and buy, and the value of the outcomes is shown after selling fees, so the profit is one you could actually make.
  • Craft the inputs too. The craft chain (the cascade) drills into how to make the required inputs themselves — sometimes the cheapest route to a Classified is two trade-ups deep, not a direct purchase.

Walkthrough

How to Use the Reverse Trade-Up Calculator

  1. 01

    Pick the target skin you want to craft

    Use the target picker to search the catalog and select the exact CS2 skin variant you want to land. The picker only surfaces variants that have a valid source rarity below them, so anything you can pick is something the contract can actually produce.

  2. 02

    Set the highest float you want

    Type a float, drag the slider across the skin's wear bands, or tap a wear preset (the highest float that still lands in that wear, where inputs are cheapest). The recipe updates as you go, and a float outside the skin's range is flagged instead of computed.

  3. 03

    Toggle StatTrak if the target is StatTrak

    Flip the StatTrak switch on if you want a StatTrak output. The calculator will only price StatTrak inputs and outcomes, and remember: every one of the 10 inputs has to be StatTrak — the contract refuses mixed lots.

  4. 04

    Read the answer — cost, value, profit and the ten inputs

    The summary shows what the contract costs, what it's worth after selling fees, the profit and your chance of the target. The float budget explains how low your inputs need to be on average, the cheapest-ten list gives the actual listings to buy (each links to its market), and the outcomes table shows every possible result with its float and value.

  5. 05

    Open "Craft the inputs instead" to go a rarity deeper

    The cascade drills down recursively: how do you produce each input? Pick an input, then any input at the level below, and the chain recomputes. Use it to compare buying inputs outright versus crafting them via a sub-trade-up.

  6. 06

    Share or save your recipe

    Hit Copy link to copy a URL that encodes the target, float, StatTrak flag and your full cascade chain, or Open in trade-up calculator to load the ten inputs into the forward calculator and save it there.

Cascade

Reading the Cascade Tree

The "Craft the inputs instead" section under the results — the cascade — is the most powerful and most underused part of the reverse calculator. Each level recursively asks the same question one rarity lower: "and how do I trade up to this required input?" That makes it the natural tool for evaluating multi-step crafting paths.

Picking a candidate at any depth

Each level shows the candidates for the input directly above it. Click a different candidate and the chain below recomputes against the new pick. Use this to compare two crafting paths side by side: pick the cheapest input first, then walk down to see whether the next level's recipe is also cheap.

When to crawl deeper, when to stop

A cascade level is worth descending only while the next-rarity-down inputs are meaningfully cheaper than the level above. If a Restricted input costs $4 and the Mil-Spec recipe under it costs $3.80 to run, the trade-up cascade saves you nothing — just buy the Restricted. The cascade exists to surface those decisions instantly.

Sharing a chosen branch

Your full cascade chain is encoded in the URL parameter ?c=, alongside the target (?t=), float (?f=) and StatTrak flag (?st=). Hit the Copy link button to grab a URL that reproduces your exact picks on any device — the cleanest way to send a friend a crafting recipe.

Reference

Reverse Trade-Up Glossary

Target
The specific skin variant you want the contract to produce. Souvenirs are excluded; everything else with a valid source rarity below it is fair game.
Target Float
The highest float you want the resulting skin to have; the recipe lands at or below it. Must fall inside the target skin's min/max range — the calculator flags anything outside.
avgNormalized
The single 0–1 value the contract demands as the average of your normalized inputs. The calculator back-solves it from your target float and the target skin's range.
Candidate
A skin that's eligible to be a trade-up input — same collection, one rarity below the target, matching StatTrak status. Each candidate carries its own required float.
Max Float
The highest float a candidate can have if all ten inputs are that skin. Different candidates get different max floats because their float ranges differ. When you mix inputs, one can go above its max as long as others sit below theirs.
Outcome
Any skin the contract can produce — your chosen target plus every other eligible skin at the next rarity in the same collection. Each outcome has its own probability and resulting float.
Contract Cost
The price of the ten cheapest live listings, mixed across skins and floats, whose average lands on your float. When the markets don't list enough copies, it falls back to an estimate for ten copies of the cheapest single input.
Expected Value (EV)
The probability-weighted average sale price of every possible outcome, shown after selling fees. Compare it to the contract cost to see whether the contract pays on average.
Cascade (craft chain)
A recursive view of how to produce the inputs themselves. Each level shows the inputs one rarity lower; pick a different one and the chain below recomputes.

Strategy

Pro Tips for Reverse Trade-Ups

  • 01
    Target wide-range skins for flexible recipes. Skins with float ranges like [0.00, 1.00] accept far more avgNormalized values inside [0, 1] than narrow-range skins do. Targets with wide ranges fail the "unreachable" check less often, and their candidate inputs are easier to source at the required float.
  • 02
    Compare contract cost and value after fees — they answer different questions. The contract cost tells you what the ten inputs cost today; the value after fees tells you what the contract pays out on average once you sell. A $40 contract worth $50 after fees is profitable. A $40 contract worth $25 is a hobby, not a business.
  • 03
    Stop cascading once the price stops dropping. The craft chain is most useful when each level's input is meaningfully cheaper than the level above it. If a Restricted candidate is $4 and its Mil-Spec sub-recipe also runs $3.80, you're not saving money — close the cascade and just buy the Restricted.
  • 04
    Watch the StatTrak premium carefully. StatTrak inputs are typically 2–6× more expensive than their non-ST counterparts, but the StatTrak target sells for a similar premium. Toggle the switch and re-solve the recipe to see whether the premium clears once fees are factored in.
  • 05
    Share the URL to lock in the recipe. The Copy link button captures the target, the float, the StatTrak flag and your full craft chain. It's the cleanest way to revisit a recipe later, send it to a friend or hand it off to a buying group — no screenshots, no re-clicking.

FAQ

Frequently Asked Questions

What is a reverse trade-up calculator?
A reverse trade-up calculator works backwards from the outcome you want. You pick a target CS2 skin and the exact float you'd like to land, and the calculator tells you which 10 inputs you need, what float each one must have, and how likely the trade-up is to produce your chosen target. The forward calculator goes inputs → outcomes; the reverse calculator goes outcome → inputs.
How does the reverse calculator know what floats my inputs need?
It inverts the official CS2 contract formula. From your target float and the target skin's range it back-solves avgNormalized = (targetFloat − targetMin) / (targetMax − targetMin), then maps that single normalized average back onto each candidate input's own float range: requiredFloat = candidateMin + avgNormalized × (candidateMax − candidateMin). Every input has its own number because every skin has its own min/max.
Why does the calculator say my target float is unreachable?
Because the inverse math falls outside [0, 1]. If the target float you typed is below the target skin's minimum or above its maximum, the implied avgNormalized is out of range, which means no combination of 10 valid inputs can ever produce it. The calculator flags the field and waits for a float inside the target's range — pick one inside the valid window and the recipe resolves.
What is the cascade ("Craft the inputs instead")?
It's a recursive view of how to produce the inputs themselves. Each cascade level asks: 'and how do I trade up to this required input?' You can pick a candidate at any depth, and the calculator recomputes the chain below it. It's the fastest way to see whether the inputs you need are themselves cheap to fabricate via another trade-up, or whether buying them outright is the better play.
How does the calculator work out the contract cost and profit?
Only the average normalized float of the ten inputs matters, so the calculator searches live marketplace listings across every eligible input skin and float and picks the ten cheapest whose average still lands on your float — often a mix, where one low-float copy carries cheaper high-float ones. That total is the contract cost. The value is the probability-weighted price of every outcome after selling fees (a 5% market fee, or Steam's 5% + 10%), and profit is value minus cost. When the markets don't list enough copies, the cost falls back to an estimate for ten copies of the cheapest single input.
Can I target Factory New if I only own Field-Tested or Minimal Wear inputs?
Yes — the output float is determined by the normalized average, not by the wear tier of the inputs. A target Factory New float is reachable as long as the implied avgNormalized falls inside [0, 1] for the candidate inputs you have available. The calculator shows the highest float each input can have and finds the cheapest mix of live listings that gets there.
Does the StatTrak toggle change the recipe?
It changes the prices and which variants are considered, not the float math. With StatTrak on, the calculator only prices StatTrak inputs and StatTrak outcomes, and the resulting target is StatTrak. All 10 inputs in a StatTrak trade-up must themselves be StatTrak — mixing StatTrak and normal skins isn't allowed by the contract.
Can I reverse-engineer a Souvenir, knife or glove trade-up?
No Souvenir targets — every CS2 trade-up output is a normal skin, even when Souvenir items are used as inputs (the IEM Cologne 2026 patch made Souvenir inputs legal, but the Souvenir attribute is always stripped on craft). Knives and gloves are produced from Covert-rarity contracts in supported crates; the reverse calculator handles those targets when the next-rarity-down inputs exist. Collection-only Coverts can't be reversed because the game has nothing to trade them up from.
Why does my recipe have multiple possible outcomes — I picked one target?
A trade-up always rolls against every eligible target in the source-rarity collection at the next tier. Your target is one of those outcomes, and the calculator highlights it, but the contract can also produce any other skin in that pool with the float defined by the same avgNormalized. The outcomes table shows every possible result, its probability, its resulting float and its market price.
Do I need to sign in to use the reverse trade-up calculator?
No. The calculator is free, anonymous and runs entirely in your browser plus a public API. Signing in unlocks extras like saving forward-calculator contracts, syncing a virtual inventory and tracking completion history, but every reverse-recipe calculation, cascade exploration and shareable URL is available to logged-out visitors.
Can I share a specific recipe and cascade chain with someone else?
Yes — every change to the target, target float, StatTrak flag and cascade picks is encoded in the URL (?t=, ?f=, ?st=, ?c=). Use the Copy link button or copy the address bar; opening the URL on any device reproduces the exact same recipe and cascade branches. It's the cleanest way to send a buddy 'here's how you actually craft this skin'.
How fresh are the prices behind the cost and value numbers?
The contract cost uses live listings seen on the markets we scan in the last two days; outcome values use the same continuously refreshed cross-market medians as the rest of CSSkinLab, capped at the lowest Steam listing. The recipe re-prices every time you change the target, float, StatTrak flag or cascade picks.

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