Herein are some basics about DEBTS ;
Debt is often issued with a repayment plan (a "time to maturity" in some cases), repayment times may be between a few days (interbank cash flow management) and 50 years or longer (consumer real estate debt). The average repayment time of all worldwide outstanding debt is perhaps 10 years.
The debt-to-GDP ratio is generally expressed as a percentage, but properly has units of years, as below.
By dimensional analysis these quantities are the ratio of a stock (with dimensions of Currency) by a flow (with dimensions of Currency/Time), so they have dimensions of Time. With currency units of US Dollars (or any other currency) and time units of years (GDP per annum), this yields the ratio as having units of years, which can be interpreted as "the number of years to pay off debt, if all of GDP is devoted to debt repayment".
This interpretation must be tempered by the understanding that GDP cannot be entirely devoted to debt repayment — some must be spent on survival, at the minimum, and in general only 5–10% will be devoted to debt repayment, even during episodes such as the Great Depression, which have been interpreted as debt-deflation — and thus actual "years to repay" is debt-to-GDP divided by "fraction of GDP devoted to repayment", which will generally be 10 times as long or more than simple debt-to-GDP.
Debt-to-GDP measures the financial leverage of an economy; some economists, such as Steve Keen, advocate using it as the key measure of a credit bubble (both its level and its change – particularly of private debt and total debt), and high levels of government debt (public debt) are widely decried as fiscal irresponsibility.
One of the EURO Convergance criteria was that government debt-to-GDP be below 60%. In Malaysia, we have set it at below 55%. Currently Malaysia's DEBT vs GDP is at 53%.