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APY Calculator (Annual Percentage Yield)

Convert between APR and APY to see your true annual yield with compounding frequency factored in.

Conversion Setup

%

Converted APY Rate

5.116%
True annual cost/yield including compounding
Math Breakdown:
Starting Rate:5%
Compounding Periods (n):12
Final APY:5.116%
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What is APR (Annual Percentage Rate) vs APY (Annual Percentage Yield)?

Both APR and APY measure interest, but banks use them strategically to their advantage. APR is the simple interest rate without factoring in compounding. APY is the "effective" rate that includes the snowball effect of compounding over the year.

Mathematical Foundation

APY=(1+APRn)n−1APY = \left(1 + \frac{APR}{n}\right)^n - 1
nn= Number of compounding periods per year (e.g., 12 for monthly, 365 for daily)
APR=n⋅((1+APY)1n−1)APR = n \cdot \left((1 + APY)^{\frac{1}{n}} - 1\right)

Laws & Principles

  • The Marketing Trick (Lending): When a bank lends you money (like a mortgage or credit card), they will legally advertise the APR, not the APY. Why? Because the APR is mathematically lower, making the debt look cheaper to the consumer. But because credit cards compound daily, you are actually paying the higher APY rate.
  • The Marketing Trick (Saving): When a bank wants you to deposit money in their High-Yield Savings Account, they will heavily advertise the APY, not the APR. Why? Because compounding makes the APY look higher, making the returns look more attractive.

Step-by-Step Example Walkthrough

" A credit card advertises a 24.00% APR. The fine print says interest compounds daily (365 times a year). "

  1. APR: 24.00%
  2. n = 365
  3. Math: (1 + 0.24/365)^365 - 1
  4. Math: (1.000657)^365 - 1 = 27.11%
Final Result: Even though the big font on the envelope said 24%, the true interest rate you will pay on a carried balance over a year is 27.11% APY.

Quick Answer: What is APY and why does it matter for savings?

APY (Annual Percentage Yield) is the actual annual return on a deposit account after accounting for compounding — the interest earned on previously earned interest within the year. The formula is: APY = (1 + APR ÷ n)n − 1. APY is the metric the Truth in Savings Act requires US banks to disclose for all deposit accounts, precisely because it reflects what you truly earn. A savings account advertising 5.00% APR compounded monthly actually yields 5.116% APY — your $10,000 grows to $10,511.62 after 12 months, not $10,500.00. At 20-year time horizons, this seemingly small difference compounds dramatically: a 5.116% APY on $50,000 grows to $137,418 vs $133,592 at 5.000% simple interest — a $3,826 difference from compounding alone.

APY Growth: $10,000 at Various Rates & Time Horizons

APY 1 Year 5 Years 10 Years 20 Years 30 Years
1.00% $10,100 $10,510 $11,046 $12,202 $13,478
2.50% $10,250 $11,314 $12,801 $16,386 $20,976
5.00% $10,500 $12,763 $16,289 $26,533 $43,219
5.25% $10,525 $12,919 $16,710 $27,922 $46,662
5.50% $10,550 $13,070 $17,081 $29,178 $49,840
Formula: FV = PV × (1 + APY)n. Values rounded to nearest $1. APY is the effective annual rate — no additional compounding calculation needed.

Savings Account APY Comparison by Account Type

Account Type Typical APY Range Compounding FDIC Insured Liquidity
Traditional Savings 0.01–0.50% Monthly Yes ($250k) High (full access)
High-Yield Savings (HYSA) 4.50–5.50% Daily or Monthly Yes ($250k) High (full access)
Money Market Account (MMA) 3.00–5.25% Daily or Monthly Yes ($250k) High (check writing)
6-Month CD 4.50–5.35% Daily Yes ($250k) Locked (penalty)
1-Year CD 4.75–5.50% Daily Yes ($250k) Locked (penalty)
5-Year CD 4.00–4.75% Daily Yes ($250k) Locked (heavy penalty)
Treasury Bills (3-month) 4.20–5.40% Discount (lump sum) Gov’t backed Tradeable (secondary)
Rates as of 2024–2025 high-rate environment. APY varies by institution. Always verify current rates at the FDIC BankFind suite or institution websites before committing.

Pro Tips for Maximizing Your APY

Do This

  • ✓Subtract the inflation rate from APY to find your real yield before comparing options. A 5.00% APY sounds attractive, but if CPI inflation is running at 3.5%, your real purchasing-power gain is only approximately 1.45% (exactly: (1.0500/1.0350) − 1 = 1.45%). In 2022–2023, when inflation peaked at 8–9% but savings rates were still 0.5–1.0%, real APY was deeply negative: savers were losing 7+ percentage points of real purchasing power annually. Always keep real yield in mind, especially during inflationary periods — sometimes Treasury Inflation-Protected Securities (TIPS) or I-Bonds offer better real yields than traditional savings accounts.
  • ✓Use a CD ladder to capture high APY without locking all funds into a single maturity. Divide savings evenly across 3-month, 6-month, 1-year, and 2-year CDs. As each CD matures, reinvest at the prevailing best rate. A $40,000 allocation split into $10,000 in each tier ensures a CD matures every 3 months — giving you liquidity access points while maintaining the higher APY of term deposits. When rates are rising, short-term CDs let you reinvest at higher rates faster; when rates are falling, locking in longer-term CDs before the drop preserves your yield.

Avoid This

  • ✗Don't leave large balances in traditional bank savings accounts paying 0.01–0.50% APY. The difference between a 0.50% APY traditional savings account and a 5.00% APY HYSA on $50,000 over 5 years: $50,000 × ((1.005)5 − 1) = $1,253 in interest vs $50,000 × ((1.05)5 − 1) = $13,814 in interest — a $12,561 difference by simply switching banks. HYSAs from online banks often pay 8–10× the national average APY with the same FDIC insurance as traditional banks. There is no meaningful risk or downside to switching an emergency fund or short-term savings to an HYSA.
  • ✗Don't assume the headline APY applies to your entire balance — check for tiered rate structures. Some money market accounts and savings products use tiered APY: e.g., 5.00% APY on the first $10,000, 4.50% on $10,001–$50,000, and 3.00% on amounts above $50,000. If you deposit $75,000 assuming 5.00% APY throughout, your blended rate is: (10,000×5.00% + 40,000×4.50% + 25,000×3.00%) ÷ 75,000 = 4.17% blended APY — significantly below the advertised headline rate. Always read the rate sheet, especially for deposits above any quoted threshold amount.

Frequently Asked Questions

How much interest does 5% APY earn on $10,000 per month?

At 5.00% APY compounded monthly, a $10,000 balance earns approximately $40.74 per month in month 1. The exact monthly calculation: the monthly rate = (1 + 0.05)1/12 − 1 = 0.4074%, so month 1 interest = $10,000 × 0.004074 = $40.74. Because interest compounds, each subsequent month earns slightly more (month 2: $40.91, month 3: $41.08, etc.). After 12 months at 5.00% APY, your $10,000 grows to $10,500.00 — exactly $500 more, since APY already accounts for compounding within the year. This is why APY is the unambiguous metric: $10,000 × 5.00% APY = precisely $500 annual interest, regardless of compounding frequency.

What is the best APY available for savings accounts right now?

APY on savings accounts closely tracks the Federal Funds Rate set by the Federal Reserve. In the high-rate environment of 2023–2024/2025, top HYSA accounts from online banks (Ally, Marcus, SoFi, Discover, Apple Savings) offered 4.50–5.50% APY, while top 1-year CDs reached 5.00–5.55% APY. Traditional brick-and-mortar banks lagged significantly (0.01–0.50% APY). When the Fed cuts rates, HYSA APYs fall quickly because most are variable-rate products; CD rates become fixed at the time of purchase. To find the highest current APY: use aggregator sites (Bankrate, NerdWallet, DepositAccounts.com) and verify directly with the institution before opening an account — promotional APYs sometimes have balance minimums or limited-time offers.

Is APY taxable? How does interest from a savings account get taxed?

Yes — interest earned from savings accounts, money market accounts, and CDs is taxable as ordinary income in the US in the year it is credited to your account (even if you don’t withdraw it). Banks report interest above $10 on Form 1099-INT. Your after-tax APY depends on your marginal tax bracket: at a 5.00% APY with a 22% marginal rate, your after-tax yield is 5.00% × (1 − 0.22) = 3.90% after-tax APY. At 37% (top bracket): 5.00% × 0.63 = 3.15%. Notable exceptions: US Treasury bills and bonds are exempt from state and local income taxes (but taxable at the federal level), which can make T-bills superior to HYSAs for high-income earners in high-tax states like California or New York. I-Bonds are federally taxable but exempt from state tax, and you can defer the tax until redemption.

Can I calculate future savings value using APY directly, without converting to a monthly rate?

Yes — APY simplifies future value calculations. For whole-year periods: FV = PV × (1 + APY)years. This works directly because APY already incorporates all intra-year compounding into a single annual factor. Example: $25,000 at 5.25% APY for 4 years = $25,000 × (1.0525)4 = $25,000 × 1.2293 = $30,733. For fractions of a year, the calculation is technically more complex because APY is defined on an annual basis and the compounding within the year isn’t uniform. For monthly precision, use the monthly periodic rate instead: monthly rate = (1 + APY)1/12 − 1, and FV = PV × (1 + monthly rate)months. For practical planning purposes on savings accounts (not high-stakes financial modeling), using FV = PV × (1 + APY)years is accurate for complete years and within 0.1% for partial years.

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