How crypto compound interest works & why reinvesting matters
Compound interest is the engine behind almost every long-term crypto-yield strategy. When you stake, lend or park assets in an Earn product and reinvest the rewards instead of withdrawing them, each payout joins your principal and immediately starts earning its own rewards. That "interest on interest" is what separates compounding from simple interest, where only your original deposit ever earns.
The effect looks modest at first and then becomes dramatic. At a steady 8% APR, a balance that compounds daily roughly doubles in a little under nine years from compounding alone — and every extra year is worth more than the last, because you're earning on a bigger base. The flip side is just as important: if you withdraw your rewards each period, you fall back to simple interest and forfeit most of that long-run growth. Reinvesting is the single biggest lever you control, which is why "auto-compounding" products that restake rewards for you can meaningfully beat ones that pay out to a wallet you rarely touch.
Two things decide how powerful the snowball becomes: how high the rate is and how often it compounds. This calculator lets you test both, plus a recurring contribution, so you can see a realistic projection rather than a back-of-the-napkin guess.
How to use this calculator
- Enter your starting amount. Use the USD value of what you're putting to work today so the result is easy to read.
- Add the APR advertised by the staking or Earn product — the nominal annual rate, not the APY.
- Pick the compounding frequency. Daily matches most exchange Earn and liquid-staking products; choose weekly, monthly, quarterly or yearly to match how often your rewards are actually paid and reinvested.
- Set the duration in years. Longer horizons show the snowball most clearly.
- Optionally add a recurring contribution — the amount you top up at each compounding period (for example, dollar-cost-averaging more into the same position).
Everything updates instantly. The headline shows your final balance; below it you get the total you contributed, the interest earned on top, your effective APY, and a year-by-year breakdown so you can see the curve steepen.
The formula
For a one-off deposit, compound interest uses the standard formula:
where P is your principal, r is the annual rate (APR) as a decimal, n is the number of compounding periods per year, and t is the number of years. The term r/n is the rate earned each period, and the exponent n · t is the total number of periods. If you add a fixed contribution C each period, this calculator also adds the future value of that stream, C × [((1 + r/n)^(n·t) − 1) ÷ (r/n)], on top of the compounded principal.
A worked example
Suppose you stake $1,000 at 8% APR, compounding daily, for 5 years, with no recurring contribution. Here P = 1000, r = 0.08, n = 365 and t = 5. The per-period rate is 0.08 ÷ 365 ≈ 0.0002192, applied over 365 × 5 = 1,825 periods:
So you'd finish with about $1,491 — roughly $491 of interest on your original $1,000. The effective APY is (1 + 0.08/365)^365 − 1 ≈ 8.33%, noticeably higher than the 8% headline APR purely because the rewards compound daily. Compare that to simple 8% interest, which would pay only $400 over five years — the extra ~$91 is the compounding at work, and it grows faster the longer you stay invested.
APR vs. APY — always compare on APY
APR (annual percentage rate) is the nominal, headline rate before compounding is taken into account. APY (annual percentage yield) is what you actually earn once compounding is included. Because platforms can quote either number, comparing two products on different bases is misleading — an 8% APY is a better deal than an 8% APR.
The relationship is fixed by the formula APY = (1 + r/n)^n − 1. At 8% APR, daily compounding gives an APY of about 8.33%; monthly compounding gives about 8.30%; yearly compounding gives exactly 8.00% (with no compounding, APR and APY are identical). The rule of thumb: always convert everything to APY before you compare, and check whether a product auto-compounds or whether you have to manually reinvest to realise that APY at all.
How compounding frequency changes the result
More frequent compounding lets your rewards start earning sooner, so it always produces a higher balance at the same nominal APR. But the effect has diminishing returns — the jump from yearly to monthly is far bigger than from daily to "continuously". On a $1,000 deposit at 8% APR over 5 years, the final balance lands roughly at:
- Yearly → about $1,469 (APY 8.00%)
- Quarterly → about $1,486 (APY ≈ 8.24%)
- Monthly → about $1,489 (APY ≈ 8.30%)
- Weekly → about $1,490 (APY ≈ 8.32%)
- Daily → about $1,491 (APY ≈ 8.33%)
The practical takeaway: don't overpay attention to "daily vs. weekly" marketing. The rate itself, the time horizon and whether you actually reinvest matter far more than squeezing the last basis point out of compounding frequency.
Realistic crypto yield sources — and their risks
The number you type into the APR box has to come from somewhere real. The main sustainable sources of crypto yield are:
- Staking (proof-of-stake networks like Ethereum, Solana or Cosmos). You help secure the network and earn protocol rewards, often in the low-to-mid single digits. Risks include slashing (losing stake for validator misbehaviour), lock-up / unbonding periods where you can't sell, and the token's own price volatility.
- Lending (CeFi platforms or DeFi protocols like Aave). You earn interest from borrowers. Rates float with borrowing demand. Risks include smart-contract bugs, platform insolvency or counterparty default, and liquidity crunches where withdrawals are paused.
- Exchange Earn products. Convenient, auto-compounding wrappers around staking and lending. Risks are mainly custodial — you're trusting the exchange to hold and deploy your assets — plus the underlying staking/lending risks.
- Liquidity provision & yield farming. Higher headline yields from trading fees and incentives, but exposed to impermanent loss and far more smart-contract risk. Use our impermanent loss calculator before committing.
In every case the yield is variable, not fixed, and it's denominated in a token whose price can fall. Earning 8% on an asset that drops 30% is still a loss in dollar terms — always think about total return, not just the yield.
Why "guaranteed" high APYs are a red flag
Sustainable on-chain yield is funded by real economic activity: staking rewards, lending demand and trading fees. That naturally lands somewhere from low single digits to, occasionally, low double digits. When a platform advertises fixed, guaranteed double-digit returns — or triple-digit APYs — be sceptical. Those numbers are usually propped up by aggressive token emissions (you're paid in a token that's being inflated), by taking on hidden risk, or, in the worst cases, by paying earlier depositors with newer deposits.
Healthy yield is honest about being variable. Treat the word "guaranteed" as a warning, prefer transparent platforms that explain where the yield comes from, never deposit more than you can afford to lose, and remember that an APY you can't explain is one you don't understand.