Health Factor

What is a Health Factor, and how does it differ from the Collateralization Ratio covered in an earlier article?

The Over-Collateralization mechanism covered in an earlier article requires a borrower to maintain a minimum collateralization ratio (say, collateral value must exceed 150% of the borrowed amount) — the collateralization ratio itself is a relatively intuitive proportional concept, collateral value divided by borrowed amount. A health factor, building on this, further integrates the variable of 'the Liquidation threshold' into the calculation formula too — not purely comparing the proportion of collateral to borrowed amount, but also factoring in the threshold of 'how much this specific collateral asset can actually be borrowed against,' calculating a number that more precisely reflects 'how much buffer space remains before triggering liquidation.'

The key difference from a pure collateralization ratio lies in 'whether the liquidation Trigger Condition has already been built into the number itself': a collateralization ratio tells you 'how many times your borrowed amount your collateral is worth,' but doesn't directly tell you 'how far away from triggering liquidation,' since different collateral assets could have different acceptable liquidation thresholds; a health factor, by contrast, multiplies this threshold directly into the formula, letting you just look at this single number, without needing to separately verify what this asset's liquidation threshold is set to, and directly know 'is it safe right now' plus 'how much safety Margin remains' — a health factor below 1 directly corresponds to the clear action-trigger point of a position entering the liquidatable range.

Why does a Health Factor exist, and what problem is it trying to solve?

As covered in an earlier article, different collateral assets, due to differing volatility and liquidity depth, usually get assigned different Liquidation threshold settings by a protocol — a lower-volatility, deeper-liquidity asset (such as a mainstream Stablecoin) might have a relatively looser liquidation threshold set; a higher-volatility asset would have a more conservative liquidation threshold set. If a borrower uses multiple different assets as collateral simultaneously, with each asset applying a different liquidation threshold, purely looking at the vague proportion of 'total collateral value divided by total borrowed amount' can't accurately reflect how far this combined position actually is from triggering liquidation.

What a health factor aims to solve is exactly this problem of 'multiple collateral assets, each with a different threshold, hard to accurately assess risk with a single proportion': by weighting each collateral asset according to its own liquidation threshold, then integrating them into a single number, regardless of how complex a borrower's collateral combination is, or how many different assets are involved, it can be condensed into a unified, directly comparable concrete indicator. This, to some extent, simplifies a risk state that would originally require separately verifying several variables to understand into a single number understandable at a glance, substantially lowering the cognitive burden a borrower needs to bear when monitoring their own position's safety.

How is a Health Factor specifically calculated, and what does a real calculation example look like?

A health factor's standard calculation formula is: Health Factor = (Total Collateral Value × Weighted Average Liquidation Threshold) ÷ Total Borrow Value. The 'weighted average liquidation threshold' within this formula refers to, if a borrower uses multiple assets as collateral simultaneously, calculating a comprehensive weighted threshold according to each asset's respective value proportion and liquidation threshold, rather than purely applying a single asset's threshold figure.

To illustrate with a concrete example: say a borrower deposits ether worth $10,000 as collateral, with this asset's liquidation threshold set at 80%, and the borrower borrows $6,000 worth of a Stablecoin — the health factor's calculation would be (10,000 × 0.8) ÷ 6,000 = 1.333. This 1.333 means the collateral value, after subtracting the liquidation threshold's buffer space, still exceeds the borrowed amount by roughly 33% — to some extent representing this position still has a certain safety Margin, not a state in danger of being liquidated at any moment.

Worth noting: this figure continuously changes as the collateral's and borrowed asset's respective market value fluctuates — if collateral price drops, or the borrowed asset's price rises (meaning the borrower genuinely owes more in substance), the health factor correspondingly declines; conversely, if collateral price rises, the health factor correspondingly rises too. When the health factor falls below 1, it means this position has entered the liquidatable range — some protocols design the more refined tiered liquidation ratio covered in an earlier article, such as a newer protocol version possibly designed so that a health factor within a specific range only triggers a partial liquidation, rather than a one-time full liquidation, to some extent lowering the impact a single liquidation causes a borrower.

What's the practical impact of a Health Factor on everyday users, and how can you effectively monitor and manage your own health factor?

For any user with a borrowed position, the health factor is the most direct, most worth-continuously-watching concrete number for assessing 'how far away from being liquidated' — compared to separately verifying multiple variables like Collateralization Ratio and Liquidation threshold, directly watching this single number lets you more efficiently grasp your own position's safety state. Most protocols' official interface directly displays this number, with no need to calculate it manually yourself.

A few concrete approaches when actually managing a health factor: set a minimum health factor alert line you can accept yourself (say, 1.5 or 2.0, rather than only starting to get nervous once approaching 1) — once market volatility pushes the health factor close to this alert line, actively take action, choosing to either add collateral or partially repay, either approach able to bring the health factor back up; make good use of some third-party services' automated monitoring and response tools covered in an earlier article, letting a system automatically execute a repayment operation once the health factor falls below a threshold you've set yourself, no need to watch the market yourself at all times; and understand a health factor is a dynamic number, not a fixed value calculated once and left alone — especially under the extreme scenario of sharp market volatility or tightened liquidity covered in an earlier article, a health factor could substantially decline within an extremely short time. Ordinarily maintaining a higher health factor buffer space effectively lowers your probability of getting liquidated under this kind of extreme scenario.