Source: Mckinsey Institute. Link to the full report below (in PDF). The chart in question is on page 10.
http://www.mckinsey....full_report.pdf
copied from another forum of doomongers
Your link doesn't work, but I found the graph anyway.
It's not really accurate though, so here's my estimates using figures from 2009 estimates (CIA world factbook because I'm cool and wanted to use one source).
UK public debt: 68.5%
Japan public debt: 192.1%
UK GDP: $2,198,000,000,000
Japan GDP: $5,049,000,000,000
Therefore, UK public debt: $1,505,630,000,000
Japan public debt: $9,699,129,000,000
UK private debt: $9,088,000,000,000
Japan private debt: $2,132,000,000,000
UK total: $10,593,630,000,000
Japan total: $11,831,129,000,000
It's a bit misleading though because the majority of the debts are in different places for each country. Our massive private debt is much more manageable as private debt than it would be as public debt, where as if the situation were reversed we probably would be in a similar situation as Greece (although for different reasons).