Conclusion
For someone in the 30.0% tax bracket, a tax-free yield of 5.00% is functionally equivalent to a taxable investment earning 7.14%. You would need a taxable instrument offering at least 7.14% to beat this tax-free bond.
Tax Equivalent Yield (TEY)
7.14%
To match your 5.00% tax-free bond, a taxable FD must offer at least 7.14% before taxes.