401(k) Growth Calculator

About this calculator

A 401(k) is a US employer-sponsored retirement account that grows through your own payroll contributions, an employer match, and investment returns compounding over years or decades. This calculator projects your account balance forward by combining your current balance, ongoing contributions (as a dollar amount or percentage of salary), any employer match, and an assumed annual rate of return, compounding the whole mix year over year.

Because the employer match is effectively free money and the growth is tax-deferred, small changes made early — bumping your contribution rate, or making sure you capture the full match — compound into large differences by retirement age. Employees use a projection like this to sanity-check whether they're on track for retirement and to see concretely how much an extra percentage point of contribution is worth decades from now.