This LSRR makes better sense than a percent of peak earning, yes.  I could live on 1/8 as much as our peak earning income, and would be doing great at 30%.  individual circumstances.  The peak years make up for us spending 22 years between us in university, and the many lean years doing a business startup not to mention the debt of school and business and west coast home.  Looking at what we actually spend on living is the better measure, which is what the LSRR at least tries to do. good article