How can someone realistically retire in about 15 years on a 50% savings rate?

Saving half your take-home pay works because of a simple symmetry: every year you live on one paycheck's worth, you also bank an equal amount, so each working year roughly funds a future year of retirement — and your investments compound on top. At a 50% savings rate, with returns near 5% real and a 4% withdrawal afterward, the math lands around 16–17 years to financial independence from a near-zero start. It's faster if you already have savings or your returns run higher. The hard part isn't the formula; it's sustaining a lifestyle that costs only half your income, usually by keeping housing and transportation modest and avoiding lifestyle inflation as you earn raises. A 50% rate also means your required nest egg is small relative to your salary, which compounds the speed. Model your timeline at wealthserene.com/tools/fire-calculator.