WARNING: These are proof-of-concept calculators designed to give a general idea of how taxes are calculated in the simplest of scenarios. They should in no way be considered advice, or binding, or predictive. Consult a tax professional for actual advice.
Do you have a workplace pension but still want to invest to supplement that, and you're not sure if you should invest in an RRSP, or keep your investments in an unregistered account? The RRSP will give you tax-back today at your marginal rate, but you'll pay tax on your withdrawals at your retirement marginal rate. Okay, but what if you take a gap-year between retirement and collecting a pension? You could withdraw your whole RRSP and pay your average tax rate on that; then collect your pension the next year. What about that Scenario?
Check out the Year by Year RRSP vs Uniregistered Retirement Savings Calculator to answer questions like these.
Okay, but for today: if you get some money and wonder if you should keep it in an unregistered account, add it to your RRSP, or your TFSA, and the tax implications if you get dividend, interest, or capital gains interest in each of those types of accounts; check out the more general Tax Calculator.