DeFi health factor

For educational purposes only; not investment advice. Investing may result in loss.

Direct answer

A DeFi health factor is an account-level measure of how much liquidation-threshold-adjusted collateral covers current debt. In Aave’s model, a value above 1 means the position is not yet liquidatable, while a value below 1 makes it eligible for liquidation. A value near 1 has little room for adverse price moves or further interest accrual.

The number is not a universal credit score or a guarantee against loss. Its definition, prices, parameters, rounding, and liquidation process belong to a specific protocol deployment. Compound III, for example, tests whether an account has negative liquidity under liquidation collateral factors and uses an absorb process rather than presenting Aave’s formula as a universal standard.

Loan-to-value and liquidation threshold are also different. LTV limits initial borrowing capacity; the liquidation threshold defines when an existing position becomes liquidatable. The gap between them is a protocol-defined buffer, not spare cash owned by the borrower.

How it works

For an Aave-style position with collateral assets i and debt assets j, the teaching form is:

health factor = sum(collateral_i value * liquidation threshold_i) / sum(debt_j value)

This is equivalent to total collateral value * weighted average liquidation threshold / total debt value. Every asset value must use the protocol’s accepted oracle price, units, and enabled-collateral status. Collateral that is supplied but not enabled, or is not eligible in the relevant market or mode, may contribute nothing.

The numerator falls when collateral prices fall, collateral is withdrawn, or an asset stops counting as collateral. The denominator rises when debt interest accrues, more debt is borrowed, or a borrowed asset appreciates against the valuation unit. Repaying debt or adding eligible collateral usually increases the health factor, but the exact result depends on transaction execution and the current parameters.

Before acting on a displayed number, verify the chain and market, account, oracle valuation, enabled collateral, debt including accrued interest, asset-specific thresholds, efficiency or isolation mode, and pending governance or risk-parameter changes. A wallet or dashboard can lag the on-chain state.

Worked example

Assume one position has $10,000 of eligible ETH collateral, a liquidation threshold of 80%, and $6,000 of debt. Its health factor is:

$10,000 * 80% / $6,000 = 1.333

• If the collateral value falls by 20% to $8,000 while debt and parameters stay fixed, the health factor becomes $8,000 * 80% / $6,000 = 1.067.
• At $7,500 of collateral, the health factor is exactly 1. Any further decline makes it less than 1 under these simplified assumptions.
• If debt grows while collateral stays at $10,000, the same boundary is reached at $8,000 of debt.

The example excludes oracle update timing, interest between observation and execution, fees, mode restrictions, parameter changes, and transaction ordering. A real liquidation may be partial or full and may transfer a liquidation bonus or penalty, depending on the deployed protocol rules.

Risks

• No universal safe level: A buffer suitable for highly correlated assets may be inadequate for volatile or weakly correlated collateral and debt.
• Oracle and market gap risk: The protocol uses its configured oracle, not necessarily the price seen on an exchange. Price gaps and delayed transactions can cross the boundary before a user reacts.
• Accruing and repricing debt: Interest increases debt over time, and a non-stable borrowed asset can rise in value even when collateral does not fall.
• Parameter and mode risk: Governance or authorized risk managers may change thresholds, caps, eligibility, or mode settings. Moving an account between modes can change the calculation.
• Liquidation loss: Liquidation can seize collateral at a bonus or discount for the liquidator, add fees or slippage, and leave the borrower with less collateral even if the remaining account becomes healthy.
• Execution and automation risk: Congestion, failed transactions, insufficient gas, frontend outages, and faulty auto-repay or auto-top-up systems can prevent a planned rescue.

Common misconceptions

Myth 1: A health factor of 1.5 means collateral can fall 50%

If only the adjusted collateral value changes and debt stays fixed, the simplified decline to the boundary is 1 - 1 / health factor. At 1.5, that is about 33.3%, not 50%. Multiple assets, debt repricing, interest, thresholds, and oracle behavior can change the result.

Myth 2: Any value above 1 is safe

Above 1 means not currently eligible under that protocol’s calculation; it does not provide a universal safety margin. A fast market move, oracle update, interest accrual, or transaction delay can remove a narrow buffer.

Myth 3: Supply yield offsets borrow interest in the health factor

Yield may increase a supplied token balance under some designs, but the health factor uses the protocol’s current collateral and debt accounting. Displayed net APY does not replace the solvency calculation, and incentive rewards may not count as collateral at all.

Myth 4: Every lending protocol uses the same formula and liquidation flow

Aave documents a health-factor ratio and permissionless liquidation below its boundary. Compound III instead determines negative liquidity with liquidation collateral factors and lets an address call absorb, transferring debt and collateral through protocol reserves. Always use the deployed protocol’s rules.

Related topics

• Collateral ratio
• Liquidation
• Liquidation bonus
• Oracle price staleness
• DeFi interest rate model

Sources

• Health Factor & Liquidations - Aave (accessed: 2026-08-20)
• Borrow Tokens - Aave (accessed: 2026-08-20)
• Compound III Docs: Liquidation - Compound Finance (accessed: 2026-08-20)