When people talk about the debt to GDP ratio being 60% to GDP, I assume that they are comparing the public debt to GDP. 

When people talk about the debt to GDP ratio being 90% or more, I assume they are including the official debt amount to GDP.  The official debt includes public debt and the amounts they pretend to owe to trust funds.  The amount we owe to trust funds is an "I owe me".  The federal government cannot owe money to itself.

Both of these debt numbers are wrong.  Neither one includes the more than $5 trillion debt owed to veterans and federal employees in the form of retirement benefits.  Neither one includes the more than $18 trillion owed to our seniors in the form of Social Security and the more than $33 trillion owed for Medicare benefits.

Keep in mind the amounts the federal government owes for Social Security and Medicare benefits are not reported as liabilities on the federal balance sheet.  Governmental officials (except for those running for office) have determined that the federal government owes nobody any Social Security or Medicare benefits beyond the checks that are currently written.