Compound Interest
Compound interest is interest earned on both your original balance and the interest already added, so growth accelerates over time. It rewards starting early and leaving money untouched, since each period builds on a larger base. The same mechanism works against you on debt. Watching a savings balance climb month after month makes the long-term power of compounding tangible.
Related terms
An interest rate is the percentage charged on borrowed money or paid on savings over a period, usually expressed annually. On debt it sets how fast a balance grows; on savings it determines how quickly your money earns more. Knowing the rates attached to your accounts helps you decide which debts to clear first and where saved money works hardest.
Your savings rate is the share of your income you set aside rather than spend, usually shown as a percentage. It is one of the strongest predictors of long-term financial security, often more important than how much you earn. Tracking income and saving together lets you calculate the rate each month and nudge it upward by trimming spending or directing windfalls to goals.
An emergency fund is a cash reserve set aside for unexpected costs like car repairs, medical bills, or sudden loss of income. Most guidance suggests three to six months of essential expenses, kept somewhere easy to access. Building it as a dedicated savings goal protects you from sliding into debt when life goes wrong, and tracking progress keeps the target in sight.
Learn more
Track it in real life
See how eTrackly's wallets, budgets and goals put concepts like this into practice — privately, on your own device.
Explore the app