TFSAs and RRSPs help shelter your investment returns from taxes helping you grow your wealth faster.
TFSA contributions are not tax deductible but you do not have to pay taxes on the money you withdraw. With an RRSP, contributions are tax deductible but any withdrawals are considered income and you have to pay taxes on them.
See also: TFSA v. RRSP Infographic
If your marginal tax rate when you make an RRSP contribution is the same as the tax rate when you make a withdrawal, TFSAs and RRSPs work out to be the same.
If your tax rate is lower at the time of withdrawal than at the time of contribution, the RRSP is the better option. But if your tax rate on withdrawal is higher than when you contributed, the TFSA will be the better option.
Note that the calculations in this calculator do not factor in the effect of RRSP income withdrawals on Old Age Security and other government benefits and credits.
Use this calculator to see how your marginal tax rate and whether you invest or spend your RRSP tax refund affects the growth of your TFSA or RRSP.