Also called several other long names: Debt to Total Capitalization, Long Term Debt to Capital Ratio, and Long Term Capitalization Ratio, the Long Term Debt to Total Capitalization Ratio measures the percentage of the company's Total Assets that are financed with long term debt.
For this ratio, Long Term Debt and Total Stockholders Equity are both considered long-term, as the equity provided by stockholders is part of the total capitalization (full debt load) of the company.