Lending APR calculator
In a DeFi lending protocol like Venus, supplying bStocks earns interest, and you can borrow other assets against them as collateral, but you pay borrow interest and face liquidation risk. Enter supplied principal and supply APR for annual interest income, amount borrowed and borrow APR for annual interest cost, to get the net spread; then add the LTV for a liquidation warning. Use the rates you see on the protocol's page; this page builds in no fixed rate and uploads no data.
Net spread = supply interest − borrow cost
*20% spot fee discount; the actual rate shown on Binance's page applies and may change with policy.
How the lending income and cost are calculated
Two lines: annual interest income = supplied principal × supply APR; annual interest cost = amount borrowed × borrow APR; subtracting one from the other gives the net spread. The supply APR is generally lower than the borrow APR, so it is hard to net a positive spread by 'supplying then borrowing' alone; you usually borrow to do something else (add leverage, free up cash), not to capture the spread itself.
The LTV (loan-to-value) is the most important safety metric in lending: it equals 'amount borrowed ÷ collateral value'. When the collateral (your bStocks, say) falls in price, or the borrow interest accrues, the LTV rises; once it hits the protocol's liquidation threshold, part of the collateral is force-sold to repay the debt, plus a liquidation penalty. Stock tokens are quite volatile, so be extra careful here.
The higher the LTV, the closer to liquidation. In a sharp drop, collateral value shrinks instantly and the LTV can blow past the liquidation line within minutes. Keep a buffer (many people hold LTV below half the liquidation line) and reserve cash to top up at any time. The exact liquidation line and penalty follow the protocol's page.
For other DeFi risks such as impermanent loss, compare with Binance Academy. For the full steps and parameters, see lending bStocks on Venus.
Who lending suits
Anyone who knows why they want to borrow, can watch the LTV, and can stomach having collateral liquidated. Beginners should start with the 'supply to earn interest' side only, and consider borrowing once they are comfortable. To look at the LP side, use the LP yield estimator; for on-chain action costs, use the gas estimator.