EAR Calculator - Effective Annual Interest Rate

The effective annual rate, or EAR, shows the actual annual impact of a quoted nominal rate after intra-year compounding. This EAR Calculator converts a nominal annual percentage and a compounding frequency into a rate that can be compared fairly across savings accounts, loans, bonds, and other interest-bearing products. A nominal rate alone does not show the full picture when interest is added to the balance more than once each year. Monthly or daily compounding lets earlier interest earn additional interest before the year ends, making the effective annual rate higher than the stated nominal rate when the rate is positive. The formula is EAR equals one plus the nominal rate divided by the number of compounding periods, raised to that number of periods, minus one. A nominal 12% rate compounded monthly becomes approximately 12.68% effective annually: each month earns 1%, and the balance grows slightly on prior months' interest. With annual compounding, the nominal and effective rates are the same because interest is added only once. The calculator also displays the periodic rate and the number of compounding periods so the relationship is transparent. Use EAR when comparing products that quote rates with different frequencies. A 6% nominal rate compounded monthly is not directly equal to a 6% rate compounded annually. Read account disclosures carefully because banks may use terms such as APY, annual equivalent rate, or effective annual yield, while loans can use APR with fee and compounding conventions that differ by jurisdiction. The calculation here isolates compounding only. It does not include origination fees, account fees, promotional-rate conditions, taxes, withdrawals, late charges, or minimum-balance requirements. For borrowing decisions, a higher EAR generally represents a higher annual cost when all else is equal. For deposits or investments, a higher effective rate may generate more interest, but liquidity, deposit protection, credit risk, maturity, and access restrictions still matter. Enter percentages as ordinary percentage values, so type 8.5 for 8.5%, not 0.085. The calculator provides a mathematical comparison, not a product recommendation or a replacement for contract terms. For long time horizons, test several rates and remember that compounding frequency affects the annual rate less than a material difference in the nominal rate itself.