For those with children aged 0-17, as you contemplate whether or not you want to make a RRSP contribution in the next couple of weeks.... add the amount from the below grid to your normal marginal tax rate to get the real value of your RRSP contribution.
For example, a household making $100k with 3 kids would have an extra 8% tax benefit on top of the marginal tax rate of the contributor. So if the contributing spouse had a 30% marginal tax rate that would mean the RRSP contribution is actually worth 38%.
Note: if household income is too high, there will be no CCB and the above breaks down. Please comment below if you'd like to know where that point is for different situations (ie. tell me how much income you'd need to still get CCB if I have 3 kids, aged 2, 4, and 7.. to which I would reply $262k household)