68% of works aren’t engaged in their job and likely dread the idea of working until their 60s. Using Mr Money Mustache’s shockingly simple math behind early retirement, I’ve been able to lower my expenses (as tracked by Mint.com) enough to retire in 2 years by age 35.

His math assumes a $0 net worth but if you have debt or assets, you can use OnTrajectory.com to calculate your years until retirement. The Trinity Study indicated a 4% withdrawal rate will survive a 30-year retirement, but by retiring in our 30s we’re talking closer to a 60-year retirement! Using Karsten Jeske’s, Big ERN from EarlyRetirementNow.com, calculations, a 3.6% of assets safe withdrawal rate, or saving a nestegg of about 28 times your expenses, has a 95% chance of outlasting a 60-year retirement.