Crypto APR, APY & Compound Interest Calculator

How the Crypto APR, APY & Compound Interest Calculator works

Short answer: APR is the nominal yearly rate without compounding; APY is the effective yearly return once interest is reinvested. APY = (1 + APR / n)^n − 1, where n is the number of compounding periods per year. An 8% APR becomes 8.30% APY with monthly and 8.33% with daily compounding. The gap widens as the rate and the compounding frequency rise.

This calculator converts a nominal APR into an effective APY for annual, monthly or daily compounding, then projects how a starting balance grows with a fixed monthly contribution. It suits anyone comparing staking, savings or lending yields quoted in APR and APY.

What you enter

• Initial principal (USD), default 10,000
• Nominal APR %, default 8 (the calculation is bounded to −99% to 1,000%)
• Investment years, default 3 (converted to whole months, up to 100 years)
• Monthly contribution (USD), default 200 (negative values count as 0; withdrawals are not modeled)
• Compounding: Annual, Monthly or Daily (default Daily)

What it shows

• APY for the chosen compounding frequency
• Final balance after the chosen number of months
• Total contributed: principal plus all monthly contributions
• Compound earnings: final balance minus total contributed

How to use it

1. Enter the starting amount in USD.
2. Enter the APR quoted by the product.
3. Pick the compounding frequency the product actually uses.
4. Enter the horizon in years and any fixed monthly top-up.
5. Read the APY and compare the final balance with the total you put in.

Formula

r = APR / 100, n = 1, 12 or 365. APY = ((1 + r / n)^n − 1) × 100. Months = round(years × 12). Each month: balance = balance × (1 + r / n)^(n / 12), then balance = balance + monthly contribution. Total contributed = principal + monthly contribution × months. Compound earnings = final balance − total contributed.

Worked example

Hypothetical: 10,000 USD at 8% APR. APY is 8.00% with annual, 8.30% with monthly and 8.33% with daily compounding, so after one year without top-ups the balance is about 10,800, 10,830 or 10,832.78 USD. With the defaults (daily compounding, 200 USD a month for 3 years): total contributed = 10,000 + 200 × 36 = 17,200 USD, final balance ≈ 20,822.43 USD, compound earnings ≈ 3,622.43 USD.

How to read the result

• Compare products by APY, not APR: two offers with the same APR pay differently if they compound at different frequencies.
• Going from monthly to daily compounding adds little at single-digit rates (8.30% versus 8.33% at 8% APR); the rate itself matters far more.
• Compound earnings show interest earned on interest and on contributions; a long horizon raises them faster than the principal alone.
• A quoted APY can be converted back: APR = n × ((1 + APY)^(1 / n) − 1).

Limits and cautions

• The projection assumes the rate stays fixed for the whole horizon; crypto yields usually change often.
• Results are in USD of the deposited asset's value only if that asset is a stablecoin; for volatile tokens the token-price change can outweigh any interest.
• Platform default, smart-contract failure, depegs, lock-ups, withdrawal fees and taxes are not included.
• Contributions are added at the end of each month and earn interest from the next month; even with annual compounding, the tool grows the balance monthly by (1 + APR)^(1/12), so mid-year contributions earn slightly more than with a strict once-a-year interest credit.

Common questions

What is the difference between APR and APY in crypto?

APR is the simple yearly rate; APY includes the effect of reinvesting interest. With any compounding more often than once a year, APY is higher than APR.

How do I convert APR to APY?

Use APY = (1 + APR / n)^n − 1, with n the number of compounding periods per year. For 10% APR compounded daily, APY = (1 + 0.10 / 365)^365 − 1 ≈ 10.52%.

Is a higher APY always better?

Not by itself. Unusually high yields often come with token-inflation, lock-up, platform or smart-contract risk that can cost more than the extra interest.

Does daily compounding make a big difference?

At typical rates the gain over monthly compounding is small: at 8% APR it is 8.33% versus 8.30% APY. The difference grows only at very high rates.