A practical crypto loan calculator walkthrough with formulas, three worked LTV examples, and stress tests so you know your costs before you borrow.
Arkadii Kaminskyi
Arkadii Kaminskyi
Head of Operations at Sats Terminal
Head of Operations at Sats Terminal with 5 years of experience in crypto. Specializes in DeFi, yield farming, and borrowing — has reviewed 50+ crypto products.
A crypto loan calculator is the difference between borrowing with a clear head and borrowing on vibes. Before you ever sign a transaction, you should know exactly how much you can borrow against your Bitcoin, what your liquidation price is, what the loan will cost per month, and how much room you have if BTC drops 20 percent overnight. This guide is a practical, step-by-step walkthrough of every input a serious crypto loan calculator needs, the formulas that actually drive the numbers, and three fully worked examples at conservative, moderate, and aggressive loan-to-value ratios. By the end, you will be able to estimate your borrowing costs and risk on the back of a napkin, then verify the result inside Borrow by Sats Terminal before clicking confirm.
Bitcoin-backed loans look simple from the outside: you deposit BTC, you receive USDC, you pay interest, you repay, you get your collateral back. Underneath that surface, there are at least a dozen variables that determine whether the loan is a smart financial decision or a slow-motion liquidation. Price volatility, variable interest rates, oracle latency, gas costs, bridging fees, origination fees, the gap between a lender's maximum LTV and its liquidation LTV — each of these inputs can change your effective cost by hundreds or thousands of dollars on a mid-sized loan.
A crypto loan calculator forces you to confront all of those variables in one place. It turns "I want to borrow against my BTC" into "I will borrow 30,000 USDC against 0.6 BTC at 6.5 percent APR with a liquidation price of 51,200 USD and a monthly interest cost of 162.50 USD." That second sentence is something you can stress test, compare to alternatives, and defend to yourself six months later when markets get noisy. The first sentence is hope.
If you want a conceptual primer before diving into the arithmetic, start with how Bitcoin-backed loans work and how LTV ratios affect your position. This article assumes you already know what a loan is — it focuses on the math.
At minimum, the output of a calculator should include: the maximum borrow amount at your target LTV, the liquidation price of your collateral, the monthly and annual interest cost in stablecoin terms, total origination and gas costs, and the buffer between current price and liquidation price expressed both as a dollar gap and a percentage drop. Anything less and you are guessing.
Before we touch a single formula, let's enumerate every input. Skipping any one of these is how borrowers get surprised. A complete crypto loan calculator needs the following fields, and you should be able to fill in each one before submitting a real transaction.
What are you posting? On Borrow by Sats Terminal, the answer is almost always native BTC, which the platform auto-bridges and wraps into wBTC, BTCB, or cbBTC depending on which chain offers the best terms. The wrapped form matters because liquidity, oracle quality, and lender appetite differ across wrappers. The collateral amount is denominated in BTC (e.g., 0.5 BTC, 1.25 BTC), and the calculator multiplies by the current price to get a USD value.
Use the spot price your lender's oracle reports, not the price on your favorite exchange. A Chainlink-fed Aave v3 market may read a slightly different price than Coinbase or Binance, especially during volatile periods. For a calculator, use a conservative round number — for the examples in this article we will use 70,000 USD per BTC as an illustrative figure. Always recompute against live oracle prices before signing.
Loan-to-value ratio is the size of your loan divided by the value of your collateral. If you post 1 BTC at 70,000 USD and borrow 35,000 USDC, your starting LTV is 50 percent. Target LTV is the LTV you want to start at — it should always be meaningfully lower than the lender's max LTV. For an in-depth treatment, see our guide to optimizing your LTV ratio.
Each market has a hard cap above which the lender will not let you borrow. Conservative BTC markets on Aave v3 often cap around 70 to 73 percent. Morpho Blue markets are configurable and range widely. CeFi desks may cap at 50 to 60 percent. Your target LTV must be below this number — usually well below.
This is the threshold at which the protocol or desk will start unwinding your collateral. It is typically 3 to 8 percentage points above the max borrow LTV. The liquidation LTV is the single most important number for survival risk because it determines your liquidation price.
DeFi protocols like Aave v3 and Morpho Blue offer perpetual, open-term loans — there is no fixed maturity. CeFi desks may offer 30, 90, 180, or 365-day fixed terms. A perpetual loan gives flexibility but exposes you to rate changes; a fixed-term loan locks in the rate and the repayment date.
Variable rates float with utilization — when borrowing demand spikes, your rate spikes too. Fixed rates lock in a number for the term of the loan. Read variable vs fixed interest rates for the full breakdown. A calculator should let you stress test both: best-case, expected-case, and worst-case rate paths.
Some platforms charge an origination fee (often 0 to 1 percent of the loan amount). Aggregators like Borrow by Sats Terminal do not add a markup on top of the underlying protocol's rate — but you should always confirm by reading how to read a crypto loan offer. Platform fees and underlying protocol fees both belong in your calculator.
Every on-chain action — depositing collateral, borrowing, repaying, withdrawing — costs gas. On Ethereum mainnet during a busy hour, a deposit-and-borrow round trip can run 30 to 80 USD or more. On BASE, Arbitrum, Polygon, Optimism, or BSC, the same flow may be cents to a few dollars. A complete calculator includes an estimated gas budget, and a conservative one doubles it for buffer.
If your BTC needs to be wrapped and routed to a different chain to access a better rate, there is a bridging step. Auto bridging on Borrow handles the routing, but the cost — typically a fraction of a percent plus gas on both sides — still belongs in your math. See bridging and wrapping Bitcoin for mechanics.
If you are borrowing USDC to redeploy it — into a stablecoin yield strategy, a real-world asset position, or another DeFi market — the yield you expect to earn is part of the equation. Net cost of the loan equals interest paid minus yield earned. Be honest about realistic, sustainable rates here. A 4.5 to 6 percent stablecoin yield is plausible in many environments; a 25 percent farm probably is not durable.
With the inputs defined, here are the equations that turn them into actionable numbers. Every crypto loan calculator worth its salt is built on these three formulas plus a few derivations.
LTV = loan_amount / (collateral_amount × collateral_price)
If you have 1 BTC at 70,000 USD and you want to borrow 28,000 USDC, your LTV is 28,000 / (1 × 70,000) = 0.40, or 40 percent. Inverting the formula tells you the maximum loan at a target LTV: loan_amount = LTV × collateral_amount × collateral_price. Bookmark our loan-to-value ratio glossary entry for quick reference.
liquidation_price = loan_amount / (liquidation_LTV × collateral_amount)
This is the price at which your position becomes liquidatable. If you borrow 28,000 USDC against 1 BTC and the lender's liquidation LTV is 0.78, then your liquidation price is 28,000 / (0.78 × 1) = 35,897 USD. Below that price, the protocol begins selling your collateral to repay the loan. The percentage drop from current price to liquidation price is your buffer: (70,000 − 35,897) / 70,000 = 48.7 percent.
monthly_interest ≈ loan_amount × APR / 12
This is an approximation that ignores intra-month compounding. For variable-rate DeFi loans where interest accrues per block, a more precise daily compounding formula is monthly_interest = loan × ((1 + APR/365)^30 − 1). For most practical purposes the simple version is within a few cents on a four-figure loan.
health_factor = (collateral_value × liquidation_LTV) / loan_amount
A health factor above 1 means the position is safe; at 1 it is at the liquidation threshold; below 1 it is being liquidated. Aave v3 displays this number prominently. See our health factor glossary and how to monitor loan health on Borrow.
buffer_pct = (current_price − liquidation_price) / current_price
A buffer of 50 percent or more is conservative; 30 to 40 percent is moderate; below 25 percent is aggressive territory and demands active management.
net_annual_cost = (loan × borrow_APR) − (loan × redeploy_APY) + origination_fees + gas + bridging
If your borrow APR is 6.5 percent and you redeploy at a sustainable 4.5 percent stablecoin yield, the carry cost is 2 percent per year — plus fees. Whether that is worth it depends on the optionality you are buying.
Now we put the formulas to work. For all three examples, assume:
Loan amount = 0.25 × 1.0 × 70,000 = 17,500 USDC.
Liquidation price = 17,500 / (0.78 × 1.0) = 22,436 USD.
Buffer = (70,000 − 22,436) / 70,000 = 67.9 percent. BTC would have to fall by more than two-thirds before liquidation — historically a once-per-cycle event.
Monthly interest = 17,500 × 0.065 / 12 = 94.79 USD. Annual interest ≈ 1,137.50 USD. Plus 25 USD in gas and bridging once.
If you redeploy the 17,500 USDC at a sustainable 5 percent stablecoin yield, you earn ~875 USD per year, leaving a net carry cost of roughly 262 USD plus fees. The position is exceptionally safe and exists primarily to free up dollar liquidity without selling BTC.
Loan amount = 0.45 × 1.0 × 70,000 = 31,500 USDC.
Liquidation price = 31,500 / (0.78 × 1.0) = 40,385 USD.
Buffer = (70,000 − 40,385) / 70,000 = 42.3 percent. A 40 percent BTC drawdown is possible in any cycle — manageable, but you need to be paying attention.
Monthly interest = 31,500 × 0.065 / 12 = 170.63 USD. Annual interest ≈ 2,047.50 USD.
This is a typical "use case" loan: cover a renovation, fund tuition, smooth out cash flow. The borrower has meaningful margin but should set price alerts at, say, 50,000 and 45,000 USD and have a plan to add collateral or repay if BTC falls 20 percent. See managing liquidation risk for the playbook.
Loan amount = 0.65 × 1.0 × 70,000 = 45,500 USDC.
Liquidation price = 45,500 / (0.78 × 1.0) = 58,333 USD.
Buffer = (70,000 − 58,333) / 70,000 = 16.7 percent. A relatively normal weekly drawdown can put you at risk. This is a position that requires active monitoring, automated alerts, and ideally a topping-up reserve.
Monthly interest = 45,500 × 0.065 / 12 = 246.46 USD. Annual interest ≈ 2,957.50 USD.
An aggressive LTV is appropriate only when the borrower has high conviction that BTC will not drop materially during the loan term, has fresh USDC ready to repay or top up, and is using the loan for something genuinely high-value (e.g., short-term bridge financing they will close out within weeks). It is not a "set and forget" configuration. Reduce the risk profile by reading how to reduce liquidation risk.
| Metric | Conservative (25% LTV) | Moderate (45% LTV) | Aggressive (65% LTV) |
|---|---|---|---|
| Collateral | 1.0 BTC | 1.0 BTC | 1.0 BTC |
| Collateral value | 70,000 USD | 70,000 USD | 70,000 USD |
| Loan amount | 17,500 USDC | 31,500 USDC | 45,500 USDC |
| Starting LTV | 25.0% | 45.0% | 65.0% |
| Liquidation LTV | 78.0% | 78.0% | 78.0% |
| Liquidation price | 22,436 USD | 40,385 USD | 58,333 USD |
| Buffer to liquidation | 67.9% | 42.3% | 16.7% |
| Monthly interest @ 6.5% | 94.79 USD | 170.63 USD | 246.46 USD |
| Annual interest | 1,137.50 USD | 2,047.50 USD | 2,957.50 USD |
| Health factor at start | 3.12 | 1.73 | 1.20 |
| Risk profile | Very safe | Manageable | Active management required |
Let's flip the question and ask: at what BTC price does your collateral value equal the loan plus interest? This is the "break-even" exit price if you intended to hold the loan for one year and repay using the collateral itself (a worst case where you cannot bring fresh USDC).
| Scenario | Loan + 1y interest | Break-even BTC price (1 BTC collateral) | Liquidation price | Cushion above liquidation |
|---|---|---|---|---|
| Conservative | 18,637.50 USD | 18,637.50 USD | 22,436 USD | Break-even is below liquidation, so you would be forced out first; in practice this means liquidation, not voluntary close, in extreme drawdowns |
| Moderate | 33,547.50 USD | 33,547.50 USD | 40,385 USD | Same dynamic — liquidation triggers earlier than break-even on collateral-only repayment |
| Aggressive | 48,457.50 USD | 48,457.50 USD | 58,333 USD | Same dynamic, even tighter |
The lesson: in every case, your liquidation price is reached before your break-even price (as long as liquidation LTV is below 100 percent, which it always is). That is the entire point of over-collateralization — it protects the lender. For you, it means you should never plan to "let it ride" through a drawdown and repay with collateral. Plan to repay with fresh stablecoins, or accept that a deep drawdown forces a liquidation.
Even decent crypto loan calculator tools tend to oversimplify. Here are the most common omissions and errors. Watch for them in any tool you use, and add the missing piece manually.
Most calculators show a flat APR. In reality, variable-rate DeFi loans can move 200 to 500 basis points in a single week of high utilization. A loan that was quoted at 6.5 percent might cost you 9 or 10 percent during a borrow demand spike. Always model a "rate stress" scenario — what does the loan cost if the APR doubles for two months? For Example B above, a doubling to 13 percent for 60 days adds roughly 113 USD on top of the base case. See crypto lending rates explained.
A liquidation event tends to coincide with a network congestion event — exactly when you most need to top up collateral or repay, gas is most expensive. If your plan to defend the position depends on submitting a transaction in 10 minutes during a flash crash, model gas at 5x to 10x baseline. On L2s this is less painful but still real.
Lending protocols read prices from oracles like Chainlink that update on threshold (e.g., 0.5 percent move) or heartbeat (e.g., once per hour). During a fast crash, the oracle price can lag the spot market by several minutes and several percent. That works for and against you: liquidation may trigger later than spot would suggest, but it also means your "buffer" calculated against spot is not the same as the buffer the oracle sees.
Some CeFi calculators bake origination fees into the APR display, which makes the rate look different than it does on the term sheet. Always ask: what is the headline APR, what is the origination fee in basis points, and what is the all-in cost including bridging and gas? Read how crypto lending rates are determined to understand the components.
A naive calculator that uses max LTV to compute liquidation price will tell you the wrong number. Liquidation always occurs at the liquidation LTV, which is higher than the max borrow LTV. Make sure you are using the right number — and if you cannot find the liquidation LTV in the documentation, do not borrow on that platform.
If you borrow USDC and USDC depegs to 0.95 USD temporarily, your nominal loan in dollar terms is still 1.00 USDC per 1 USDC owed — you owe USDC, not dollars. But if you intended to redeploy into a yield strategy that also denominates in USDC, your real-world purchasing power has dropped. Model this. See understanding stablecoin risks.
Once you have a base-case calculation, stress test it. The point is not to predict the future — it is to ensure that you can survive realistic adverse scenarios without being forced to act in panic.
BTC drops from 70,000 to 56,000 USD (a normal correction). For Example B (45 percent starting LTV), new LTV = 31,500 / (1.0 × 56,000) = 56.3 percent. Health factor drops from 1.73 to 1.39. Still safe, but you are now closer to the lender's max LTV. For Example C (65 percent), new LTV = 81.3 percent — already past the liquidation threshold of 78 percent. Liquidation likely. This is exactly why aggressive LTVs require either active management or a strong directional view.
BTC drops to 45,500 USD over a weekend. Example A (25 percent): new LTV = 38.5 percent — comfortable. Example B (45 percent): new LTV = 69.2 percent — uncomfortably close to the 73 percent borrow cap and 78 percent liquidation. Time to act: repay a portion or add collateral. Example C: liquidated days ago.
BTC at 35,000 USD. Example A (25 percent): new LTV = 50 percent — still inside max borrow, but the position is now medium-risk and the borrower may want to repay or top up. Example B (45 percent): liquidated. Example C: liquidated.
This scenario is often more dangerous than a single deep drop because borrowers get complacent. Each oscillation toward the downside chews through the buffer; if rates also rise during the period, the loan grows faster than the borrower expects. Variable-rate borrowers should reserve cash to repay or top up during these stretches.
A practical exercise: build a 5x3 grid in a spreadsheet with rows for BTC drawdown (−10%, −20%, −30%, −40%, −50%) and columns for your three target LTVs. In each cell, compute new LTV and flag whether the position is comfortable, at risk, or liquidated. Carry that grid in your head before you sign. If you would rather not build it from scratch, the live position view inside Borrow renders an equivalent visualization once your loan is open.
Borrow by Sats Terminal is an aggregator, not a lender. When you connect, deposit native BTC, and request a quote, Borrow scans loan offers across DeFi protocols (Aave v3 and Morpho Blue) and supported CeFi desks across BASE, Ethereum, Arbitrum, Polygon, Optimism, and BSC, then surfaces the most competitive terms in one view. Because the platform is self-custodial — your wallet is a Privy-secured wallet you control — Borrow itself never takes possession of your BTC. Read more in meet Borrow by Sats Terminal.
The relevance for a crypto loan calculator: the inputs that vary across lenders — max LTV, liquidation LTV, current borrow APR, origination fee — are pulled live for every market and displayed alongside each quote. You do not have to maintain a spreadsheet of which Aave v3 wBTC market is currently 6.4 percent versus which Morpho Blue cbBTC vault is 5.8 percent; the comparison is rendered in real time. Auto bridging and wrapping handle the BTC routing, so the borrowable USDC lands on whichever chain provides the best all-in cost.
Where the calculator math from earlier in this article comes in is the second half of the decision. Borrow shows you the offers; you decide which LTV to target and which loan to take. The arithmetic of liquidation price, monthly interest, and buffer is yours to run — and once a loan is open, the position view inside Borrow continuously displays health factor, current LTV, liquidation price, and oracle price so you can monitor without rebuilding the spreadsheet. For a deeper look at the underlying mechanics, see how lending aggregators find best rates and understanding collateral and LTV.
Borrow does not guarantee a rate, run a custodial book, require KYC, or markup the underlying protocol's APR. It does not promise yield on your collateral — the BTC sits as collateral in the chosen lending market and earns no yield. It does not provide tax advice. And it does not predict prices: the stress testing above is something every borrower should do themselves, every time. For a quick reference on the platform itself, see our liquidation glossary entry.
Common Questions
A crypto loan calculator is a tool that translates your inputs — collateral asset and amount, current price, target LTV, lender's max and liquidation LTV, interest rate, fees, and gas — into the practical numbers that determine whether the loan is a good idea: maximum borrow size, liquidation price, monthly interest cost, buffer to liquidation, and health factor. Unlike a generic loan calculator, a crypto-specific version accounts for variable rates, oracle pricing, on-chain gas, bridging costs, and over-collateralization mechanics. Treat it as a planning tool: run the numbers before borrowing, and re-run them whenever market conditions change materially.
