APY Calculator
Convert a nominal interest rate into APY, or work backward from an APY to the nominal rate, at any compounding frequency -- this calculator handles both directions.
The same nominal rate at other compounding frequencies:
| Frequency | APY |
|---|
This is a general estimate, not financial, investment, or tax advice.
How to Use This Calculator
Choose whether you want to find an APY from a nominal rate, or the reverse. Enter the rate and pick the compounding frequency. The result shows the converted rate, plus a comparison table showing what the same nominal rate would produce at daily, monthly, quarterly, and annual compounding, so you can see how much frequency actually matters.
Why Compounding Frequency Changes the Answer
APY already includes the effect of compounding; a nominal rate alone does not. The same 5.00% nominal rate produces a slightly different APY depending on how often it compounds — more frequent compounding means interest starts earning its own interest sooner, which pushes the APY a bit higher. See How Compounding Frequency Works for a fuller breakdown, or What Is APY for the underlying regulatory definition.
Frequently Asked Questions
What's the difference between APY and APR?
APR is the nominal annual rate before compounding is applied. APY includes the effect of compounding, so for the same nominal rate, APY is always equal to or higher than APR.
Why does compounding frequency change APY?
More frequent compounding means interest gets added back to the balance more often, so it starts earning its own interest sooner. This produces a slightly higher APY for the same nominal rate.
Why do banks advertise APY instead of a nominal rate?
APY gives a standardized, apples-to-apples way to compare accounts with different compounding schedules. It's also the figure regulated under the Truth in Savings Act. See What Is APY.
Is more frequent compounding always better?
For the same nominal rate, yes, more frequent compounding produces a slightly higher APY. The practical difference between common frequencies like daily and monthly is usually small.
Does this calculator account for fees?
No. This tool converts between nominal rate and APY only. Monthly maintenance fees or minimum balance requirements can reduce your real return separately from this calculation.
Sources
- APY conversion formula — TheCalculatorSite
- More frequent compounding produces a higher APY for the same nominal rate — Caesar Cipher
How This Calculator Is Verified
Built by Cedrick Reese. Every formula on this page is checked against multiple independent sources before publishing, and cross-verified against real calculations before this page went live -- not just written once and trusted.
Last reviewed: August 25, 2026