USDT APR vs APY: What’s the Difference for Crypto Earn?

APR and APY are often used as if they mean the same thing. They do not. The difference is compounding.

For small rates and short holding periods, the gap can be minor. For longer periods, higher rates or frequent reinvestment, it becomes more noticeable.

Summary

• APR expresses a simple annualized rate without assuming compounding.

• APY expresses the annualized result after compounding under a stated frequency.

At 5% APR:

• simple annual result on 10,000 USDT = 500 USDT;

• if 5% APR were compounded daily at a constant rate, the APY would be slightly above 5%.

The crucial question is not what label a page uses. It is whether distributed interest is actually reinvested into the earning principal.

APR: The Simple Annualized Rate

APR answers: “What would this rate imply over a year before compounding?”

For 20,000 USDT at 4% APR:

20,000 × 4% = 800 USDT annualized

APR is easy to compare across products, but it does not tell you whether interest is reinvested.

APY: The Compounded Annual Result

APY answers: “What would the annual return be if interest compounds at the stated frequency?”

The general formula is:

APY = (1 + APR / n)^n − 1

where n is the number of compounding periods per year.

At 5% APR with daily compounding, the APY is approximately 5.13%.

On 10,000 USDT, that difference is roughly 13 USDT over a full year if the rate remains unchanged and daily compounding actually occurs.

Daily Payout Does Not Automatically Mean Daily Compounding

This is the most common misunderstanding.

A product can distribute interest every day without automatically putting that interest back into the earning balance.

If the daily reward lands in a Spot wallet and sits there, it is not compounding inside the earn product.

Compounding requires the reward to become part of the principal that earns future interest.

How to Check Whether a Crypto Earn Product Compounds

Look for one of these mechanisms:

• interest automatically added to principal;

• Auto-Earn or auto-subscribe enabled;

• a receipt token whose balance grows with yield;

• explicit daily/weekly compounding language in the product rules.

Do not infer compounding only from “paid daily.”

How MEXC Earn Plus Handles Interest

MEXC's current Earn Plus FAQ states that interest is calculated hourly and distributed daily. The Earn Service Agreement says distributions from Earn Plus products are added to the principal deposit amount and future distributions are based on the updated principal.

Users should rely on the current product interface and official rules for the exact reinvestment mechanics of the specific Earn Plus product they are using.

This is a stronger approach than assuming a generic APY from the words “daily distribution.”

APR vs APY Example at Different Rates

Assuming daily compounding and a constant rate:

The difference grows as the rate rises.

For a variable-rate product, however, the realized APY cannot be known in advance because future APR is unknown.

Which Number Should You Use When Comparing Products?

Use APR when you want a clean rate comparison and the products do not compound in the same way.

Use APY when:

• compounding is automatic;

• the compounding frequency is known;

• you are comparing products with similar rate assumptions.

For variable stablecoin products, it is often better to track realized return after the fact rather than estimate a precise one-year APY from a rate that can change next week.

FAQ

What is the difference between APR and APY?

APR is a simple annualized rate. APY includes the effect of compounding.

Does daily interest payment mean daily APY compounding?

No. The interest must be reinvested into the earning principal for compounding to occur.

Is APY always higher than APR?

If the rate is positive and compounding occurs more than once a year, APY is normally higher than the equivalent APR.

Which is better for comparing USDT earn products?

APR is often the cleaner first comparison. Then check whether and how the product compounds.

Is MEXC Earn Plus APR fixed?

No. MEXC states that Earn Plus APR is variable.