A retirement calculator is a tool that helps individuals estimate how much money they will need to save for retirement. By inputting information such as current savings, expected retirement age, and desired lifestyle, users can see projections of their future finances. This can help them make informed decisions about their savings strategies. These calculators often consider factors like inflation, investment growth, and Social Security benefits. Many financial institutions and websites offer free retirement calculators, making it easy for anyone to assess their retirement readiness and adjust their plans accordingly.