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📋 APY Calculator

Compare annual percentage yield across compounding frequencies: daily, monthly, quarterly, and effective rate from nominal APR.

APY — True Yield After Compounding Frequency

BrainyCalculators editorial insight — unique to this tool

APY converts a nominal annual rate into the effective yield after compounding — a 5% APR savings account compounded daily yields APY ≈ 5.127%. US banks must disclose APY on savings under Reg DD; Indian FDs quote annual rates but payout frequency (monthly vs quarterly) changes effective return. Comparing two accounts requires APY, not headline APR.

When to use this calculator

Use to compare deposit products on equal footing. For loan cost, use APR or EMI calculators instead.

Reference Value Context
5% APR, daily compound 5.127% APY Savings example
5% APR, monthly 5.116% APY Less frequent
High-yield savings (US) 4–5% APY 2024–2025 range
US Reg DD APY disclosure Mandatory on savings

Measuring purchasing power loss over time?

This page compares compounded yield. For inflation impact on future costs, use the Inflation Calculator →

What is APY?

APY (annual percentage yield) reflects effective yearly return after compounding frequency is applied to a stated nominal rate. Higher compounding frequency raises APY above the headline APR.

Use this page to compare savings accounts and CDs on an equal footing. Inflation erodes purchasing power of those returns over time; combine APY with an inflation estimate for real return.

Compound interest projects balance growth with contributions; APY focuses on rate comparison.

APY Formula

APY = (1 + APR/n)^n − 1
APR = n × ((1 + APY)^(1/n) − 1)
n = compounding periods/year APR = nominal annual rate APY = effective annual yield

Real-World Example

5% APR compounded monthly (n = 12):

APY = (1 + 0.05/12)^12 − 1
APY = (1.004167)^12 − 1
APY = 5.116%
Effective Daily Rate = 0.01370%

How the APY Calculator Works

Formula, assumptions, and calculation steps for this finance tool.

Formula Used

APY = (1 + r / n)^n - 1

Methodology

Financial calculators use time-value-of-money, rate conversion, amortization, or return formulas depending on the tool. Inputs are normalized to matching periods before the final result is calculated.

Calculation Steps

  1. Enter the principal amounts, rates, terms, or cash flows requested by the calculator.
  2. Convert annual rates to the correct monthly, daily, or yearly period when needed.
  3. Apply the finance formula for payment, return, yield, or future value.
  4. Show the result with supporting totals such as interest, gain, or balance.

Assumptions and Limits

  • Rates are assumed constant unless the calculator asks for a schedule.
  • Taxes, fees, and inflation are included only when fields are provided.
  • Financial results are estimates for planning, not investment or lending advice.

Frequently Asked Questions

APR (Annual Percentage Rate) is the stated nominal interest rate without accounting for compounding within the year. APY (Annual Percentage Yield) reflects the actual return after compounding is applied over a year. APY is always greater than or equal to APR. When comparing savings accounts, always compare APY for an accurate comparison.

More frequent compounding means interest is calculated and added to your balance more often, so future interest calculations include previously earned interest sooner. Daily compounding produces the highest effective yield, though the difference between daily and monthly compounding is typically very small (a few basis points).

Always compare APY, not APR. Two accounts may advertise the same nominal rate but have different APYs based on compounding frequency. For example, 5% APR compounded daily yields 5.127% APY, while 5% APR compounded annually yields exactly 5% APY.

Higher compounding frequency is better for savers (more frequent = higher APY). Daily compounding is the most favorable. For borrowers, less frequent compounding is better. Most high-yield savings accounts and CDs compound daily or monthly.

Real-World Applications of APY

🏦
High-Yield Savings Accounts
Compare HYSA offers: a 5.00% APR compounded daily yields 5.13% APY vs 5.00% APY compounded annually — a meaningful difference for large balances.
📜
CDs and Fixed Deposits
Certificate of deposit terms from different banks use APY for fair comparison. A 12-month CD at 5.25% APY outperforms one at 5.20% regardless of compounding structure.
💹
Money Market Accounts
MMAs often compound daily. APY lets you compare them directly to CDs and savings accounts that may compound monthly or quarterly.
🪙
Crypto & DeFi Yield
Decentralised finance protocols often quote APY. Unlike bank APY, DeFi APY is variable and not guaranteed — treat it as an approximation.
📊
Retirement Account Returns
Converting fixed income returns to APY allows comparison across annuities, bonds, and savings vehicles inside an IRA or 401(k).
🔄
APY ↔ APR Conversion
Financial professionals convert between APY and APR to standardise rate comparisons across products with different compounding structures.

Common APY Mistakes to Avoid

1
Comparing APR to APY Across Accounts
Some institutions advertise APR; others advertise APY. Comparing a 5.0% APR directly to a 5.0% APY is misleading — always convert to the same basis before comparing.
2
Assuming Continuous Compounding Is Always Available
Continuous compounding (the mathematical limit as n → ∞) is rarely offered by banks. Daily compounding is the practical maximum. The difference between daily and continuous is negligible.
3
Ignoring Minimum Balance Requirements
A high APY means little if you can't maintain the minimum balance required to earn that rate. Always check minimum balance thresholds alongside the APY.
4
Treating Variable APY as Guaranteed
Many online savings accounts and DeFi protocols have variable APY that changes with market conditions. A current APY of 5.5% may drop to 4% within months.
5
Forgetting Taxes on Interest Income
Interest from savings accounts is taxable. A 5% APY in a 22% tax bracket yields an after-tax APY of about 3.9%. For tax-advantaged accounts (Roth IRA, 401k), APY reflects true net yield.

APY by Compounding Frequency (5% APR)

Compounding Frequency Periods / Year APY $10,000 After 1 Year
Annually 1 5.000% $10,500.00
Semi-annually 2 5.063% $10,506.25
Quarterly 4 5.095% $10,509.45
Monthly 12 5.116% $10,511.62
Daily 365 5.127% $10,512.67

References

  1. Federal Deposit Insurance Corporation. Truth in Savings Act (TISA). fdic.gov
  2. Investopedia. Annual Percentage Yield (APY) Definition. investopedia.com
  3. Consumer Financial Protection Bureau. What is the difference between APR and APY? consumerfinance.gov
  4. Federal Reserve. Regulation DD — Truth in Savings. federalreserve.gov
  5. National Credit Union Administration. Understanding Savings Rates. ncua.gov

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