To find out the maximum amount you can contribute to your RRSP for the current year, refer to the notice of assessment that the Canada Revenue Agency sent you after you filed your tax return.
The maximum amount you can contribute to your RRSP is 18% of your earned1 income or the maximum annual contribution limit for the taxation year ($26,010 for 2017), whichever is lower. That said, there are a few other factors that can affect your contribution limit.
If you haven’t contributed the maximum to your RRSP in previous years, this unused contribution room will be added to your maximum contribution amount. You can find your unused contribution room on your most recent notice of assessment from the Canada Revenue Agency.
If you contributed to a pension plan or deferred profit sharing plan (DPSP) through your employer during the previous year, your RRSP contribution room is reduced. The Canada Revenue Agency calculates this reduction for you. You can find it on your notice of assessment.
If you go over your contribution limit by $2,000 or less, the CRA allows you to keep the money in your RRSP without penalty. If you over-contribute by more than $2,000, you will have to pay a tax of 1% for each month that the excess amount remains in your RRSP.