How to Use This Compound Interest Calculator
Our free compound interest calculator gives you accurate estimates in seconds. Enter your numbers above and hit Calculate — results update instantly.
All calculations use current 2026 rates and formulas. Results are estimates to help you plan — always verify with a licensed professional for final numbers.
Frequently Asked Questions
What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest. Unlike simple interest, it causes your money to grow exponentially over time.
How often does interest compound?
Interest can compound daily, monthly, quarterly, or annually. The more frequently it compounds, the more you earn. Daily compounding yields slightly more than annual compounding.
What is the Rule of 72?
The Rule of 72 estimates how long it takes to double your money. Divide 72 by your annual interest rate. At 6% annual return, your money doubles in about 12 years (72 / 6 = 12).
What is a good interest rate for savings?
High-yield savings accounts in 2026 offer 4-5% APY. Long-term stock market average returns are around 7-10% annually. CDs offer 4-5% for fixed terms.
How does compound interest differ from simple interest?
Simple interest is only calculated on the principal. Compound interest is calculated on principal plus accumulated interest. On 0,000 at 5% for 10 years: simple = 5,000, compound = 6,289.