Which calculator do you need?
Start with the free money: the 401(k) employer match calculator shows what your match is worth today and at retirement — an unclaimed match is a 50–100% instant return left on the table, and it outranks every other move in personal finance.
Then pick the account: Roth vs. Traditional compares after-tax value at retirement, driven by the only variable that actually decides it — your tax rate now versus later. At equal rates the two are mathematically identical; the calculator proves it to the dollar.
Then aim: the FIRE number calculator turns your spending into a target portfolio with an adjustable withdrawal rate (4%, 3.5%, 3%…), shows your progress, and estimates the years to get there. Pair it with the compound interest calculator to see the path, and the inflation calculator to keep the target in today’s dollars.