Compound Interest Calculator

What is compound interest?

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest — which is calculated only on the principal — compound interest grows exponentially over time.

Albert Einstein reportedly called it "the eighth wonder of the world." Whether or not the quote is accurate, the math is undeniable: compounding rewards patience.

The compound interest formula

The standard formula is:

A = P(1 + r/n)^(nt)

Where:

• A = final amount
• P = principal (initial investment)
• r = annual interest rate (as a decimal)
• n = number of times interest compounds per year
• t = time in years

How compounding frequency affects returns

The more frequently interest compounds, the more you earn. Here's an example with 100,000 SEK at 8% for 10 years:

| Frequency | Final value |

|---|---|

| Annually | ~215,892 SEK |

| Quarterly | ~220,804 SEK |

| Monthly | ~221,964 SEK |

| Daily | ~222,535 SEK |

The difference between annual and monthly compounding is nearly 6,000 SEK — without investing a single additional krona.

Why time is your most powerful variable

The longer your investment horizon, the more pronounced the compounding effect. A 25-year-old investing 100,000 SEK at 8% annually will have roughly 2.2 million SEK by age 75 — through compounding alone.

Starting 10 years later, that same investment yields only ~1 million SEK. The 10-year delay costs more than half the final value.

Realistic return expectations

For context when using this calculator:

• Savings accounts (Sweden): 2–4%
• Global index funds (long-term average): 7–10%
• Diversified equity portfolio: 6–9%
• Private equity / alternatives: 10–15%+ (with higher risk)

These are historical averages — past performance does not guarantee future returns.

Tracking your actual compounding growth

A calculator gives you projections. Findex gives you reality — your actual portfolio performance across every asset class, updated in real time. Connect your accounts and let Midas AI show you how your wealth is actually compounding.