Calculator
CS2 Knife Chance Calculator
The chance of unboxing a knife from a CS2 case is 0.26% per opening, or 1 in 391. Pick a case and a number of openings to get the probability of pulling at least one knife, and how many cases a target chance takes.
Knife chance per case
0.26%
1 in 391
After 100 cases
22.6%
chance of at least one knife
Cases for a 50% chance
271
≈ $742.54 in the Kilowatt Case
Cases for a 90% chance
900
≈ $2,466.00 in the Kilowatt Case
Knife chance calculator
Number of cases
Target chance
P(zero knives)
77.41%
P(at least one)
22.59%
P(at least two)
2.74%
Expected knives
0.256
Cases needed for a 90% chance
900≈ $2,466.00 at $2.74 per opening
At Kilowatt Case's knife odds (0.2558%, 1 in 391 per open), opening 100 cases gives approximately 22.6% chance of seeing at least one knife, with an expected 0.26 knives pulled for about $274.00 in cases and keys.
Assumptions
- Each case opening is an independent event (no pity system exists in CS2).
- P(at least one) = 1 − (1 − p)n; P(at least two) subtracts the exactly-one term from that.
- p is this case's real P(knife specifically) — the rare-special slot odds split across only the knife entries in its pool, from the same probability engine as the simulator.
- Rounding: displayed opens-for-target is the smallest integer meeting or exceeding the target.
Chance of a knife after N cases
| Cases opened | At least one knife | No knife | Cost |
|---|---|---|---|
| 1 | 0.26% | 99.74% | $2.74 |
| 10 | 2.53% | 97.47% | $27.40 |
| 25 | 6.20% | 93.80% | $68.50 |
| 50 | 12.0% | 88.0% | $137.00 |
| 100 | 22.6% | 77.4% | $274.00 |
| 250 | 47.3% | 52.7% | $685.00 |
| 500 | 72.2% | 27.8% | $1,370.00 |
| 1,000 | 92.3% | 7.7% | $2,740.00 |
P(at least one knife after N cases) = 1 − (1 − p)N, with p = 0.2558%. Cost uses the cheapest knife case to open, the Kilowatt Case, at $2.74 per opening (case + key, Steam market snapshot Oct 27, 2026).
How many cases for a knife?
| Target chance | Cases needed | Cost |
|---|---|---|
| 25% | 113 | $309.62 |
| 50% | 271 | $742.54 |
| 75% | 542 | $1,485.08 |
| 90% | 900 | $2,466.00 |
| 95% | 1,170 | $3,205.80 |
| 99% | 1,799 | $4,929.26 |
The average is one knife every 391 cases (about $1,071.34 of openings at the cheapest knife case), but an average is not a guarantee: after 391 cases there is still a 37% chance of having no knife at all.
CS2 knife odds: common questions
What are the odds of getting a knife in CS2?
0.26% per case, or 1 in 391. A knife is a Rare Special Item (the "gold" drop), which Valve's published rarity rule makes 2.5× rarer than a Covert (red) skin. The full rarity table is on CS2 case opening odds.
How many CS2 cases does it take to get a knife?
391 on average. For a 50% chance of at least one knife you need 271 cases; for 90%, 900; for 99%, 1,799. There is no number of cases that guarantees one.
What are the odds of a knife after 100 cases?
22.6% to pull at least one knife in 100 cases, so 77.4% to pull none. After 500 cases it is 72.2%, and after 1,000 it is 92.3%.
Does opening more cases change the per-case odds?
No. Every opening is an independent 0.26% roll. CS2 has no pity timer or bad-luck protection, so the 500th case has exactly the same knife chance as the first. Only the cumulative chance of having hit at least once goes up.
Do knife odds differ by case?
Not between knife cases: all 35 cases with knives in DropLabz's dataset give the same 0.26% knife chance. What changes is which knives are in the pool, how many finishes share that chance, and the price of each opening. 7 cases (Clutch Case, Glove Case, Operation Broken Fang Case and others) drop gloves instead and cannot give a knife. Compare them on CS2 knife odds by case.
What is a gold drop in CS2?
"Gold" is the community name for the Rare Special Item tier, shown with a gold colour in the case opening reel. It is always a knife or a pair of gloves, depending on the case. Its 0.26% chance is the same number this calculator uses.
Related knife tools and data
- CS2 knife odds by case: which cases drop knives, which drop gloves, and the chance of one specific knife.
- Best cases for knives: knife cases ranked by the average cost of pulling one.
- All CS2 knife types: finishes and source cases for every knife.
- Case ROI and expected value: what each case returns on average per opening.
- Case opening simulator: open cases for free and see how long a knife really takes.
- Knife trade-ups: five Covert skins for a knife instead of opening cases.