If you are not a high-income earner, and if saving 20% of your income seems implausible, or even impossible at the moment, don’t worry. Saving 20% is just a suggestion. Ideally, we would save 100% if we could. So even if you can save 20% just remember that saving something is better than nothing.
However, don’t use this as an excuse to not save at all. If you want a shot at being secure through old age and having some extra cash for things you want, then I suggest that 20% is the number you’ll want to reach or exceed.
Assuming you’re in your 20s or 30s and can earn an average investment return of 5% a year, you’ll need to save about 20% of your income to have a shot at achieving financial independence before you’re too old to enjoy it.