Compound Interest Calculator

How to use the Compound Interest Calculator

1. Enter your initial deposit or current savings balance.
2. Set the annual interest rate you expect to earn.
3. Choose how many years you plan to save or invest.
4. Optionally add a monthly contribution amount to see how regular deposits boost your growth.
5. Review the year-by-year table and chart to see your projected balance over time.

Why compounding frequency matters more at higher rates

More frequent compounding (daily or monthly versus annual) produces a slightly higher effective return at the same stated rate, because interest starts earning its own interest sooner. The difference is small at low rates and short time horizons, but it becomes more noticeable at higher rates and over long periods. This is exactly why credit card issuers, which charge relatively high rates, almost universally compound daily, while many savings products compound only monthly or quarterly.

Frequently asked questions

What's the difference between this and the Investment Return Calculator?

This tool is a more general-purpose compounding calculator (savings accounts, debt, any fixed-rate scenario); the Investment Return Calculator is specifically built for comparing investment scenarios side by side with variable contribution patterns.

Does compounding frequency (monthly vs. annually) make a big difference?

At typical savings-account rates, the difference between monthly and annual compounding over a year is usually small in absolute terms; over long horizons or higher rates, it becomes more meaningful and worth comparing directly rather than assuming it's negligible.

Can I model irregular contributions, not just a fixed monthly amount?

This tool assumes a consistent contribution schedule; for genuinely irregular contributions, running the numbers in segments (recalculating from your updated balance each time contributions change) will get you a more accurate picture than a single continuous projection.