Upgrader Odds Calculator
Exact upgrade chance, multiplier and cost per attempt. Updates live as you type.
| Multiplier | Target | Chance | Lose-streak P(5 fails) |
|---|
Upgrader odds, exactly
Skin upgraders give you chance = (your value ÷ target value) × (1 − edge), capped at a maximum (usually 80–90%). Put ◎25 towards a ◎100 skin on a 10%-edge site and you get 22.5%, not 25%. The expected value of the attempt is ◎22.50 — you pay ◎2.50 for the privilege, every time, at every multiplier.
Chaining compounds the edge
Each step pays its own 10%. Two 2× steps to reach 4× give 0.45 × 0.45 = 20.25%; a single 4× attempt gives 22.5%. The box on the right does this comparison for whatever target you've entered. The answer is always the same: if you must upgrade, do it in one jump.
Cap
The cap stops you converting a ◎100 skin into a ◎101 one at 99% — sites cap at 80–90% so the edge still bites on "safe" upgrades. Set the cap to whatever the site you're looking at uses.
What edge do real upgraders use?
Commonly 8–10%. Some show the exact figure in the upgrade panel; if not, compare the displayed chance to fair (your ÷ target) to back it out.
Is a 90% upgrade safe?
It fails 1 in 10 times and you lose the entire skin. 'Safe' in gambling means slower, not risk-free.
Does the multiplier change the expected value?
No. EV is always your item × (1 − edge). Multiplier only changes how the loss is distributed.
Which site has the best upgrader?
Look for the lowest edge and highest cap. CSGORoll's is the most used (code GETBOX); CSGOBig (code headshot) and CSGOFast (code GETCASE) have one too.
Worked example: ◎25 → ◎100
Fair chance 25%. At 10% edge: 22.5%. EV ◎22.50, expected loss ◎2.50 per attempt, 4.4 attempts to expect one success. Chaining two 2× steps instead gives 0.45 × 0.45 = 20.25% — worse by 2.25 points for the same destination.
Common mistakes
- Treating the displayed chance as fair. It already includes the edge.
- Chaining small steps 'to be safe'. Each step pays the edge again.
- Using an item's listed price as its value when it would sell for less.
Other calculators
Try the maths live
Every number here can be tested with fake coins: case opening, Roll, Upgrader, Crash.
- House edge
- The share of every wager the operator keeps over the long run. 1% edge = ◎10 expected loss per ◎1,000 wagered.
- RTP
- Return to player — the mirror of house edge. 90% RTP on a case means a 10% edge.
- Expected value (EV)
- What a bet is worth on average: sum of (payout × probability). Always below the stake on a real site.
- Variance
- How much results swing around the average. High variance = long dead runs, rare big hits.
- Provably fair
- A seed-hash system letting you verify a result was fixed before your bet. Proves honesty, not good odds.