How many reds (Coverts) do you need for a knife trade up?
Short answer: 5 reds. Since the CS2 update of October 23, 2025, exactly five Covert (red) skins – all normal or all StatTrak™ – trade up into one knife or pair of gloves from the case of one of the inputs. Ten skins are only used for the tiers below Covert.
How the chain works from blues
Players often ask “how many blues for a knife”. The full ladder with 10 skins per step is: 10 blue (Mil-Spec) → 1 purple (Restricted); 10 purple → 1 pink (Classified); 10 pink → 1 red (Covert); 5 red → knife. So one knife costs, in theory, 10 × 10 × 10 × 5 = 5,000 blues – which is why nobody does it that way. In practice you buy the 5 cheapest reds of the case whose knife pool you want.
What the odds are
Every item in the case’s pool has the same chance: 1 ÷ pool size. Older cases share a 65-item pool (1.5% each); Fever, Gallery and Kilowatt have 13-item pools (7.7% each). See every pool on the case knives pages.
What it costs today
The cheapest 5-red contracts cost roughly $175–210 and have an expected value of $100–160 – most lose money on average. The cheapest knife trade up page ranks all 43 cases with live prices.
Open the knife trade up calculator
Related questions
Can you use 10 reds for a knife?
No – the knife contract takes exactly 5. Ten Coverts is not a valid contract.
Do the 5 reds have to be from the same case?
No, but each input adds a 20% share for its own case’s pool, so mixing cases mixes the pools.
Do reds from map collections work?
No. Only Covert skins from weapon case collections have a knife pool.