The rule of thumb that many financial advisors and experts use is to contribute 10% to 15% of your annual income to your 401(k). You could also aim to contribute as much as needed to at least maximize your employer contributions through any matching program you’re offered. If you aim to retire early, your contribution rate should be as high as you can afford. For example, those who seek the FIRE strategy (financial independence, retire early) significantly cut their living costs to direct more money to their retirement fund.