http://www.fraserinstitute.ca/shared/taxcalc.asp
Follow the link:
Put in your gross income
Put in your # of dependents
Click enter and discover what you'd pay for taxes if you lived in Canada
Remember too that there are still sales taxes and other taxes in Canada, not just personal income taxes. And, remember that if you lived in Canada versus the US that your income would be significantly lower as an RN because of the rate of exchange.