Formula Library
Savings & Interest Formulas
Compound interest calculations, savings goal projections, and emergency fund planning formulas.
Coast FIRE Calculator
intermediateCalculate when you can stop saving for retirement and let compound growth do the rest.
=retirement_target / (1 + return_rate)^years_until_retirement Compound Interest (FV)
beginnerCalculate how much your savings will grow over time with compound interest.
=FV(rate/12, periods, -monthly_contribution, -initial_deposit) Emergency Fund Target
beginnerCalculate your ideal emergency fund size based on your monthly expenses and risk factors.
=monthly_expenses * months_coverage How Much Do I Need to Retire
beginnerCalculate your retirement savings target based on your expected expenses and the 25x rule.
=annual_expenses * 25 Inflation-Adjusted Value
intermediateCalculate the real purchasing power of future money by accounting for inflation.
=future_value / (1 + inflation_rate)^years Required Monthly Savings
beginnerCalculate how much you need to save each month to reach a financial goal by a target date.
=PMT(rate/12, months, -current_savings, goal) Rule of 72
beginnerQuickly estimate how long it takes for an investment to double at a given interest rate.
=72/annual_rate Safe Withdrawal Rate (4% Rule)
beginnerCalculate how much you can withdraw annually from your retirement portfolio without running out of money.
=portfolio_value * 0.04 Savings Goal Timeline
intermediateCalculate how many months it will take to reach a savings goal with regular contributions.
=NPER(rate/12, -monthly_savings, current_savings, -goal_amount)