Use this calculator to estimate how your savings can grow over time with regular contributions and compound interest.

This tool is also available in Swedish →

How the calculator works

This calculator is designed to give you a clear estimate of how your money may grow when you combine an initial amount with consistent monthly savings. You enter four key inputs: your monthly contribution, starting balance, expected annual return, and the number of years you plan to save. Based on these values, the calculator projects a future value that includes both your total contributions and the returns generated over time.

The core idea behind the calculation is compound growth. This means your money earns returns not only on what you invest, but also on the returns that accumulate along the way. The longer your time horizon, the more powerful this effect becomes. Even small monthly contributions can grow significantly when given enough time. The result is an estimate, not a guarantee. Markets fluctuate, and real-world returns will vary, but the calculator helps illustrate the long-term potential of disciplined saving.

The formula behind the calculation

The calculator uses standard financial formulas for compound interest and recurring contributions. First, your annual return is converted into an equivalent monthly rate using the expression (1 + r)^(1/12) − 1, where r represents the annual return.

Your starting amount grows according to the future value formula: it is multiplied by (1 + r)^n, where n is the number of years. This reflects how a lump sum increases over time with compound growth.

Your monthly contributions are calculated using a variation of the annuity formula. Each monthly deposit is added and then grows at the monthly rate for the remaining time period. Earlier contributions have more time to compound, which is why consistency over time matters more than timing the market. The final result combines both parts into a single projected value.

Smart ways to use this calculator

This tool is especially useful for planning long-term financial goals. You can use it to explore how much you need to save each month to reach a target amount, or how increasing your contributions impacts your outcome. It also helps you understand the value of starting early, as even a few extra years can make a noticeable difference.

Another practical use is comparing different return assumptions. By testing conservative and optimistic scenarios, you can build a more realistic expectation of future outcomes. This makes the calculator a helpful guide for decision-making, whether you are saving for retirement, a home, or general wealth building. Ultimately, the calculator is best used as a planning tool to visualize growth and motivate consistent saving over time.