No matter how much or how little money you make each year, the date you'll be able to retire depends on only one number: the percentage of your take-home pay that you save. It's obvious, but the more you save now the less you're spending. Lower lifestyle expenses means that the amount you save will last you longer in your retirement. Mr. Money Mustache has a handy chart to help you calculate how many years you'll have to work based on your savings rate.
The key insight is worth repeating: frugality now gets you double benefits. If you spend less now you will save more now, and your cost of living will be lower when you retire because you'll be used to frugal living. Here's the chart:
MMM saved 65% of his take-home pay and retired in around 10 years. I'm not doing that well, but looking at this chart sure inspires me to save more.