Your savings rate is the single biggest determinant of when you can retire.
At a 10% savings rate you need 43 working years. At 50%, only 17. At 75%, just 7.
This calculator earns its keep at decision points: before accepting a loan, comparing investment platforms, or negotiating salary. The difference between the headline figure and the true cost or return is only visible with accurate arithmetic.
The most consequential mistake is comparing financial figures that are not on the same basis — gross versus net, before-tax versus after-tax, or nominal versus inflation-adjusted. Always check whether figures you are comparing use the same definition.
A small business owner compares two financing options for new equipment: a 5-year bank loan at 5.2% versus a leasing arrangement with a monthly fee. The calculator translates both into a total cost figure, making the comparison straightforward.
50%+ for FIRE in ~17 years. 75% in ~7 years. The higher the rate, the faster financial independence.