Retirement Understanding the SECURE Act 2.0 Related Content Global vs. International: What’s the Difference? International funds invest in non-U.S. markets, while global funds may invest in U.S. stocks alongside non-U.S. stocks. Roth 401(k) vs. Traditional 401(k) This calculator compares employee contributions to a Roth 401(k) and a traditional 401(k). You May Need to Make Estimated Tax Payments If… Have income that isn’t subject to tax withholding? Or insufficient withholdings? You may have to pay estimated taxes.