Nominal vs Effective Rate Calculator

💰 How This Calculator Works

Converts between nominal (APR) and effective (APY/EAR) interest rates. Banks advertise nominal rates for loans and effective rates for savings — making comparison intentionally difficult.

🔢 Worked Examples

• 12% APR monthly → 12.68% EAR
• 5% EAR, daily compounding → 4.879% APR nominal
• Credit card 24% APR → 26.82% EAR

📋 Common Use Cases

Interest calculators cover compound interest, simple interest, and time-value-of-money concepts. Understanding the difference between nominal and effective rates — and how compounding frequency affects returns — can mean thousands of dollars difference over a savings or investment horizon.

• Comparing savings account yields by compounding frequency
• Computing the true annual rate from a monthly-quoted rate
• Projecting investment growth under different return assumptions
• Understanding the "Rule of 72" for doubling time

💡 Did You Know?

Daily compounding at 5% annual grows money to 5.127% effective rate. Compounding matters more the longer you invest — the difference between annual and daily compounding on a 30-year $10,000 investment is over $1,500.

⚠️ Common Mistake

Assuming APR = APY — they are only equal when compounded once per year. For monthly compounding (most accounts), EAR > APR.