Casinos work out their wagering requirements based on a simple formula of multiplication.
In other words, the casino will look at the amount (value) of the cash bonus added to your account, or the money that you’ve won from the free spins that they gave you.
They will then times that amount by their wagering requirement number.
Let’s consider the no deposit bonus offered by Diamond Reels Casino:
The no deposit bonus is worth €20, and the wagering requirements are twenty times (45x), your wagering requirement = €900.