A football bonus is not the same as cash in hand, so I look at what you have to wager before you can withdraw.
At Reblz, Quickz, SlotOwl, Betinferno, LuckyJungle, Monsino, Unlimit Casino and Winzie, you must wager your deposit plus bonus 6 times, at odds of 1.50 or higher, within 21 days. Each bet counts for at most 20% of the bonus.
Take a NOK 500 deposit giving you NOK 500 in bonus. You now have NOK 1,000, but NOK 1,000 times 6 means NOK 6,000 to wager before you can withdraw. That is the number to keep in view, not just the NOK 500 bonus.
Trivelabet, ProntoBet, Kumobet and Jaabet work differently: they give 100% up to €200 as a free bet instead. Only your deposit is played once, at odds of 2.0.
Winsly gives you 25% of the stake back as a free bet on each of your first seven sports bets, up to €350. Each free bet is valid for 24 hours.
The calculator works out the amount, the minimum odds and how much it is per day, so you can compare the bonus amount with the wagering required.