Crypto Savings Interest Calculator
Solve the savings interest relation Interest = Principal × (APY / 365) × Days for any of its four unknowns — interest earned, principal, APY, or term in days — with step-by-step math, a clean principal-APY-time schematic, and a projection table showing the compounded 5-year picture.
The formula computes simple day-count interest for the given term. Savings accounts compound — interest is added to the principal and earns interest on itself. This table shows what the principal would become at the same APY over 1, 3, 5, 10, 20, and 30 years, assuming the APY is compounded annually and stays constant. In practice, DeFi APYs are variable and drift down over time as a product matures.
| Horizon | Principal | Interest earned | Total value | Multiplier |
|---|
APY already includes compounding
The distinction between APR and APY matters enormously here. APR (annual percentage rate) is the simple rate — 8% APR on $10,000 earns exactly $800 in a year. APY (annual percentage yield) is the effective rate after compounding — 8% APY means the total return over a year is 8%, so you end up with $10,800 regardless of compounding frequency. DeFi savings products almost always quote APY, which is what this calculator assumes. If a product quotes APR, the actual annual return will be slightly higher after compounding, and the calculation becomes Interest = Principal × ((1 + APR/n)^n − 1) for n compounding periods.
The yield is not the risk — the platform is
An 8% APY on a stablecoin sounds attractive next to a 4% US Treasury. But the two are not comparable. A Treasury is backed by the full faith and credit of the US government; an 8% crypto savings product is backed by a smart contract, a protocol, or a company. If the smart contract is exploited, the protocol is hacked, or the company becomes insolvent, you can lose the entire principal, not just the yield. The relevant comparison is not 8% vs 4% — it is (8% × probability of survival) vs 4%. At a 5% annual probability of total loss, the risk-adjusted yield of the 8% product is only 3.6%, below the Treasury. This is the fundamental framing that separates a sophisticated crypto saver from a naïve one.
APYs decay over time
Crypto savings rates are not stable. They are driven by borrowing demand on the underlying protocol, and they fall as the product matures and more capital chases the same yield. A new pool might offer 30% APY on launch, drop to 12% after three months, and settle at 5% after a year. A CeFi desk that offered 10% in 2021 was offering 4% by 2023 — or was insolvent. This calculator uses a constant APY, which is an idealisation. For realistic planning, model the APY falling by 30–70% over the first year, and stress-test the case where it drops to zero because the product is discontinued. The projection table below shows the compounding effect at a constant rate; in reality, the curve flattens.
Compare to the risk-free rate
The only meaningful benchmark for a crypto savings yield is the risk-free rate in the same currency — usually the US Treasury bill rate for USD stablecoins. If T-bills pay 5% and a DeFi pool offers 6% APY, you are being paid 1% for taking on smart contract risk, protocol risk, and liquidity risk. That is almost certainly not enough. If T-bills pay 2% and the pool offers 8%, you are being paid 6% for the same risks — a much more interesting proposition, though still not free. The spread over the risk-free rate is the true compensation for the additional risk, and it should be the number you compare across products, not the headline APY.
How to Use This Calculator
The savings interest relation links four quantities: Interest, Principal, APY, and Days. Pick which one you want the tool to solve, then fill in the other three.
1. Choose what to solve for
Pick Interest, Principal, APY, or Days from the toggle. The calculator rearranges Interest = Principal × (APY / 365) × Days automatically for whichever you choose.
2. Use realistic presets
Presets cover the range: principals from $100 to $1M, APYs from 1% (T-bill-like) to 20% (promotional), and terms from 7 days to 5 years — spanning promotional rates, standard savings, and multi-year commitment products.
3. APY is not APR
The formula uses APY, which already incorporates compounding. If a product quotes APR instead, the actual annual return will be slightly higher after compounding, and you should use a compound-interest formula. Most crypto savings products quote APY, so this calculator matches the standard convention.
4. Read the result and verdict
The result card shows the interest earned plus the total value at the end of the term and the daily accrual rate. A colour-coded verdict classifies the APY from risk-free-rate equivalent through unsustainable promotional yield.
5. Check the projection table and schematic
The projection table shows what the same APY produces over 1, 3, 5, 10, 20, and 30 years, assuming the rate holds and compounds annually. The schematic shows the principal bar × APY box × days box = interest result circle.
6. Switch to Advanced for depth
Advanced mode adds an interest-vs-APY curve, a sensitivity check on a +1% change in each input, and companion metrics including the daily and monthly accrual rates, the effective annual rate, and the spread over the risk-free rate.
What This Tool Offers
Built around the classic savings interest relation Interest = Principal × (APY / 365) × Days, the fundamental calculation for any yield-bearing deposit.
Four-way solving
Solve for interest earned, principal, APY, or term. The calculator rearranges the formula for whichever variable you choose.
Clean savings schematic
A principal bar × APY box × days box = interest result circle, with live fills that scale to the input magnitudes and a live readout of the exact calculation.
Compounded projection table
Projects the same APY over 1, 3, 5, 10, 20, and 30 years with annual compounding, showing the interest earned, total value, and multiplier at each horizon.
Multi-unit hints
Each field shows related quantities — daily and monthly accrual, effective annual rate, and the spread over the risk-free rate.
Dual comparison charts
A cumulative interest-vs-time curve, plus an advanced interest-vs-APY curve showing how earnings scale with the rate.
APY benchmarks
Reference tables covering typical rates by product type, the APR vs APY distinction, and the platform-risk framing that separates the yield from the risk.
Reference Tables & Conversions
A live savings interest solver, a lookup grid, and typical APY ranges by product type.
Quick savings interest solver with daily accrual
Interest Lookup at Principal = $10,000, Days = 365
Computed from Interest = 10,000 × (APY / 365) × 365 with fixed principal and term.
| APY | Annual interest | Monthly accrual | Daily accrual | Total value |
|---|
Typical APY Ranges by Product Type
Representative stablecoin yield rates. Numbers shift constantly with market conditions, protocol utilization, and competitive pressure.
| Product type | Typical APY | Risk level | Notes |
|---|---|---|---|
| US Treasury bill (3-month) | 4 – 6% | Risk-free | The benchmark for all USD yields |
| Money market fund | 4 – 5.5% | Very low | Tracks T-bills minus a small fee |
| High-yield savings account (bank) | 4 – 5% | Very low | FDIC insured up to limits |
| Aave USDC (variable) | 3 – 8% | Low-medium | Utilization-driven; audited blue-chip DeFi |
| Compound USDC (variable) | 3 – 7% | Low-medium | Per-block accrual; long track record |
| Curve/Convex stable pools | 4 – 10% | Medium | LP tokens; impermanent loss negligible on stable pairs |
| Yearn / Beefy vaults | 5 – 15% | Medium | Yield aggregators; smart contract stacking risk |
| Maple / Goldfinch (fixed) | 8 – 15% | Medium-high | Undercollateralised credit; default risk |
| New-chain promotional pools | 15 – 50% | High | Token incentives; usually unsustainable |
| CeFi savings (post-2022 sector) | 4 – 10% | High | Custodial; counterparty risk; sector shrank after failures |
| High-yield "CeFi" promotional | 10 – 20%+ | Very high | The rate that killed Celsius, BlockFi, Voyager |
APR vs. APY — Why the Distinction Matters
The formula in this calculator uses APY. Understanding the difference prevents a common source of confusion in yield products.
| Feature | APR (nominal) | APY (effective) |
|---|---|---|
| Definition | Simple annual rate, no compounding | Effective annual return including compounding |
| Formula for interest | P × APR × t | P × ((1 + APR/n)^n − 1) × t, or just P × APY × t for the full year |
| Compounding frequency | Ignored | Baked in |
| Example: 8% APR daily compounding | 8.00% APR = $800 on $10,000 | 8.33% APY = $833 on $10,000 |
| Typical use | Loans, credit cards, some CeFi products | Crypto savings, DeFi yields, bank deposit products |
| Direction of error if confused | APR-understating: if you use APR as APY, you overstate interest | APY-overstating: if you use APY as APR, you understate interest |
Risk-Adjusted Yield — the Number That Actually Matters
A headline APY is meaningless without the probability of survival. The table shows the risk-adjusted yield at different probabilities of total loss.
| Headline APY | Prob. of total loss | Risk-adjusted yield | vs. 5% risk-free | Verdict |
|---|---|---|---|---|
| 8% | 0% | 8.00% | +3.00% | Attractive if the 0% is real |
| 8% | 1% | 6.92% | +1.92% | Thin but positive |
| 8% | 3% | 4.76% | −0.24% | Worse than risk-free |
| 8% | 5% | 2.60% | −2.40% | Clearly worse than T-bills |
| 15% | 5% | 9.25% | +4.25% | Attractive at this risk level |
| 15% | 10% | 3.50% | −1.50% | Worse than risk-free |
| 15% | 20% | −8.00% | −13.00% | Negative expected return |
| 20% | 15% | 2.00% | −3.00% | The classic CeFi trap |
Variable Reference
| Symbol | Meaning | Typical range | Units |
|---|---|---|---|
| Principal | Deposit amount | 1 – 1e12 | USD |
| APY | Annual percentage yield | 0.01 – 200 | % |
| Days | Term in days | 1 – 36500 | days |
| Interest | Interest earned | 0.01 – 1e12 | USD |
| Total | Principal + interest | — | USD |
| Daily rate | APY / 365 | — | % / day |
| Effective yield | Interest / Principal | — | % |
What Does Interest = Principal × (APY / 365) × Days Measure?
Crypto savings interest connects four quantities that every yield-seeking investor watches: the amount deposited (Principal), the yield offered by the product (APY), the length of time the principal is held (Days), and the resulting earnings (Interest). It is the fundamental calculation for stablecoin yield products — DeFi lending pools like Aave and Compound, yield aggregators like Yearn, CeFi savings desks, and fixed-term credit protocols like Maple and Goldfinch. It answers the simplest question in yield investing: "If I deposit this much at this rate for this long, how much do I earn?"
Savings Interest Formula
The defining relationship is:
Rearranged to solve for the other three unknowns:
APY = (Interest × 365) / (Principal × Days)
Days = (Interest × 365) / (Principal × APY)
From these, additional metrics follow directly:
Monthly accrual = Principal × (APY / 12)
Total value = Principal + Interest
Effective yield = Interest / Principal × 100
Spread over risk-free = APY − risk-free rate
Savings Interest Variables
| Symbol | Meaning | Notes |
|---|---|---|
| Principal | Deposit amount | Usually a stablecoin; yield is quoted in the same asset |
| APY | Annual percentage yield | Compounding already baked in; variable in practice |
| Days | Term length | Simple day-count accrual from this formula |
| Interest | Earnings over the term | Does not account for platform failure risk |
| Spread | APY minus risk-free rate | The true compensation for taking platform risk |
How Each Variable Affects the Outcome
Interest scales linearly with all three inputs. Doubling the principal doubles the interest. Doubling the APY doubles the interest. Doubling the term doubles the interest. This is the arithmetic of simple day-count interest, and it makes the math predictable — you can estimate any product's earnings in your head. A $10,000 deposit at 8% APY earns $2.19 per day, $66.67 per month, and $800 per year. Whatever the product, the per-day number is the one to keep in mind: it tells you exactly how much the deposit is paying you per day of exposure, which is the number that should be weighed against the daily probability of loss.
The most important practical insight is that the interest rate and the platform risk are not two separate considerations — they are the same consideration, and the relevant comparison is the risk-adjusted yield. A 15% APY product with a 10% annual probability of total loss has a risk-adjusted yield of 3.5%, which is below the risk-free rate. A 6% APY product with a 0.5% probability of loss has a risk-adjusted yield of 5.47%, which is better than the 15% product despite the much lower headline rate. The naive comparison — 15% beats 6% — is wrong, and the more dangerous kind of wrong, because it looks correct. Every yield product should be evaluated on (APY × probability of survival) minus (APY × probability of loss), and only products with a positive spread over the risk-free rate are worth holding.
A third insight: crypto savings rates decay. DeFi yields are set by supply and demand — as more capital flows into a pool, the rate falls, because the borrowing demand that pays the yield does not scale with the deposits. A new pool that launches at 30% APY will typically be at 12% within a quarter and 5% within a year as capital pours in. CeFi products have shown a different decay — some have simply failed, taking the principal with them. For long-term planning, do not extrapolate the current APY forward. Model it falling by 30–50% per year for the first two years, then plateauing at some long-run rate, and stress-test the case where the platform fails entirely. The projection table in this calculator shows what the constant-rate case looks like, which is a best case, not a base case.
Savings Interest Calculation Examples
Interest = 10,000 × (8/365) × 365 = 10,000 × 0.08 = $800.00
Interest = 10,000 × (8/365) × 30 = 10,000 × 0.006575 = $65.75
Interest = 50,000 × (5/365) × 90 = $616.44
Principal = 800 / ((8/365) × 365) = $10,000
APY = (800 × 365) / (10,000 × 365) = 0.08 = 8.00% APY
Days = (800 × 365) / (10,000 × 8) = 365 days
Total = 10,000 × (1.08)^5 = $14,693.28 (interest $4,693.28)
Frequently Asked Questions
APR (annual percentage rate) is the nominal simple rate — the rate before accounting for compounding. APY (annual percentage yield) is the effective rate after compounding, and it is the number you actually earn. If a product quotes 8% APR with daily compounding, the effective annual return is 8.33% APY, and you earn $833 on $10,000 rather than $800. If a product quotes 8% APY, you earn exactly 8% — $800 on $10,000 — because the compounding is already baked in. This calculator uses APY, which is the standard convention for crypto savings products. If you have an APR, convert it to APY first using APY = (1 + APR/n)^n − 1, where n is the number of compounding periods per year.
It comes from someone paying to borrow your stablecoins. On Aave and Compound, the yield is the borrow rate paid by traders and protocols who borrow USDC against crypto collateral. On Curve and Convex, it is trading fees plus token incentives paid to liquidity providers. On Maple and Goldfinch, it is interest paid by institutional or emerging-market borrowers. On CeFi desks, it is the return the desk earns from its own lending operations, passed through to you with a spread. This is the critical question for any yield product: who is paying this yield, and why? If the answer is "token incentives" (new tokens printed to attract deposits), the yield is a subsidy that will end. If the answer is "borrowers paying real interest," the yield reflects real economic demand. Knowing which is which is the difference between a sustainable product and a Ponzi.
There is no universal answer, but there is a useful framework. The risk-free rate for USD is the 3-month Treasury bill rate — currently 4–6% depending on the rate cycle. Anything close to that from a crypto product is either a loss-leader, a promotional rate, or a product with hidden risk. Anything 1–4% above the risk-free rate is compensating you for a moderate amount of platform risk and can be justified if you trust the protocol (Aave, Compound, MakerDAO have multi-year track records). Anything 5–10% above is compensating you for meaningful risk — smart contract exploits, undercollateralised lending, protocol insolvency — and you should size the position accordingly. Anything 15%+ above the risk-free rate should be treated as having a non-trivial probability of total loss, because the only way to pay that much is with a risky or unsustainable source of yield. The Celsius and BlockFi investors who took 10%+ APY in 2021 learned this the hard way.
It is a completely different risk profile and the numbers are not comparable. Yielding BTC or ETH means your principal fluctuates in fiat terms — a 30% BTC drawdown costs you $3,000 on a $10,000 deposit, dwarfing any interest you earned. A 3% BTC yield is $300 per year, which is noise compared to the daily price volatility. Yield on volatile assets is a way to enhance an existing position or offset some holding cost, not a way to earn passive income. Stablecoin yield is a different proposition because the principal is (approximately) stable — the yield is real earnings, not a small offset against price moves. Choose the vehicle based on your view of the underlying asset, not on which yield is higher.
Compare on three dimensions: (1) risk-adjusted yield — headline APY minus the expected loss from platform failure, which you estimate subjectively; (2) liquidity — can you withdraw at any time, or is the principal locked for a term; (3) tax treatment — interest income is usually taxed at ordinary income rates, which differ by jurisdiction. A 10% APY product that locks your capital for 12 months and is domiciled in an unclear jurisdiction is not obviously better than a 5% APY product you can withdraw from any time. Also compare the spread over the risk-free rate: a product offering 8% when T-bills pay 5% is offering 3% for the risk. The same 8% when T-bills pay 1% is offering 7% — a much more attractive proposition. The absolute number matters less than the spread.
Barely. The difference between simple interest and daily-compounded interest over 30 days at 8% APY is about $0.05 on $10,000 — a rounding error. Compounding only becomes material over multi-year horizons, where the difference between 8% simple and 8% compounded annually is over $2,000 on a 10-year $10,000 deposit. The formula in this calculator computes simple day-count interest, which matches how DeFi protocols accrue on a per-block or per-second basis. If you want the compounded version for a multi-year projection, use Total = Principal × (1 + APY)^years. The projection table below shows this compounding over 1, 3, 5, 10, 20, and 30 years.
You lose the principal. Unlike a bank deposit, which is insured by the FDIC (in the US) or equivalent deposit insurance schemes in other countries, crypto savings products are not insured. When Celsius, BlockFi, Voyager, and FTX failed in 2022, their customers lost most or all of their deposits. Recovery in bankruptcy has been slow, partial, and in some cases nonexistent. This is the single most important fact in crypto savings: the 8% APY you earn in a year can be wiped out by a single failure, and no regulatory backstop exists to make you whole. The correct way to think about it is not "8% APY" but "8% APY minus (probability of platform failure × 100%)". If you estimate a 5% chance of total loss, the risk-adjusted yield is 2.6%, which is below the risk-free rate. Diversify across multiple protocols, never deposit more than you can afford to lose entirely, and treat the yield as compensation for that risk — not as free money.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| Interest Earned | Total interest earned | coins |
| Principal | Amount of crypto deposited | coins |
| APY | Annual percentage yield offered | % |
| Days Held | Number of days the deposit was held | days |
What it means
Crypto savings accounts offer interest on deposited assets. The interest earned is calculated using the simple interest formula, applied daily based on the APY. This is used to track earnings and to compare savings platforms. Understanding this helps users choose where to deposit their crypto for yield. It is a key consideration for passive income strategies. The interest is often paid in the same asset or in a stablecoin.
Worked example
Crypto Savings Account Interest – Two Detailed Examples
Real‑World| Parameter | Value |
|---|---|
| Principal | 1 BTC |
| APY | 4% |
| Days Held | 30 |
| Parameter | Value |
|---|---|
| Principal | 10,000 USDT |
| APY | 8% |
| Days | 365 |
Common mistakes
- Principal: The initial amount deposited.
- APY: The annual percentage yield (in decimal).
- Days held: The number of days the amount is deposited.
- Interest: Simple interest – does not compound within the period.
Applications
Crypto savings account interest calculates the interest earned on crypto deposits over a period, using the APY and the holding period. This is used by platforms offering interest‑bearing accounts. Investors use it to estimate their earnings and to compare different savings products. By calculating the interest, they can optimise their cash management strategies. Understanding this formula helps in choosing between various savings options.
- Estimating earnings from crypto savings accounts
- Comparing APYs across different platforms
- Planning cash flow and interest income
- Tax reporting on interest income
- Educational understanding of crypto interest products
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