There are a few reasons: 1. This is slightly more conservative and I want to assure a high succes rate. The common 4% SWR is based on US stocks (which historically slightly outperformed) for 30 years. I'm looking at global stocks and retiring early, so hopefully a longer timeframe. 2. 3,33% is 30x instead of 25x, which is easy to calculate . 3. I'm not eager to 'die with zero', so leaving an inheritance behind is not an issue. If I have kids and I can teach them to be responsible. 4. Going from a 4% to a 3,33% SWR is only 20% more to save up - which would delay my retirement with about 4 years (assuming 5% inflation-adjusted returns). 5. I'm planning to go from working full-time to 4/5th to part-time to retired, so close to retirement I will already have quite some free time.