Free margin in one sentence
Free Margin is the portion of your account equity that is available to absorb losses and potentially open or maintain positions, after setting aside margin required by your existing trades.
To understand how it differs from nearby concepts, it helps to anchor each term to the quantity it represents, and then keep a clear boundary between stable mechanics and variable conditions.
The core definitions and how they relate
Equity (the starting point)
Equity is the account’s value after considering both:
- the balance (cash-related components), and
- unrealized profit or loss from open positions.
Unrealized profit or loss depends on current market pricing and can change even when you do nothing. Because of that, equity is the most “dynamic” input in many margin calculations.
Used Margin / Margin Requirement (the reserved part)
Used Margin (often described via Margin Requirement) is the portion of equity reserved to support your open positions. Different providers may compute this with their own formulas, but the conceptual role is consistent: it is money that is not treated as freely available.
If you open positions, used margin typically increases. If you close positions, used margin typically decreases.
Free Margin (equity minus the reserved part)
Free Margin is commonly described as:
- Free Margin = Equity − Used Margin
That definition is a stable mechanical relationship: it tells you what portion of equity remains after accounting for funds tied up as margin for current trades.
Margin Level (a ratio that signals proximity to limits)
Margin Level is typically expressed as a ratio that compares equity to used margin, for example:
- Margin Level = Equity / Used Margin
The key difference is that Free Margin is an absolute buffer (a money amount), while Margin Level is a relative measure (a ratio). Two accounts could have the same Free Margin but different Margin Level if their used margin differs, and vice versa.
Bounded comparison: adjacent concepts, side-by-side
This section links each adjacent concept to its “owner” quantity.
- Equity is the owner of the account’s value (including unrealized P/L), and it changes with pricing.
- Used Margin is the owner of funds reserved by open positions, and it changes when positions change.
- Free Margin is the owner of the leftover buffer, computed from equity and used margin.
- Margin Level is the owner of risk proximity as a ratio, computed from equity and used margin.
A useful way to remember the distinction:
- Free Margin answers: “How much equity is not reserved?”
- Margin Level answers: “How large is equity compared with what is reserved?”
Neither concept by itself predicts outcomes. They only describe different views of the same underlying relationship between equity and required/reserved margin.
Evidence by example (with explicit assumptions)
Because exact provider formulas can differ, the example uses simplified, general assumptions and focuses on the arithmetic relationships.
Assume:
- Equity = 10,000
- Used Margin = 3,000
Then:
- Free Margin = 10,000 − 3,000 = 7,000
- Margin Level = 10,000 / 3,000 ≈ 3.33
Now assume a market move causes unrealized losses so that equity falls to 8,500, while used margin stays the same (because open positions are unchanged).
Then:
- Free Margin = 8,500 − 3,000 = 5,500
- Margin Level = 8,500 / 3,000 ≈ 2.83
What changed?
- The buffer shrank (Free Margin decreased) because equity decreased.
- The ratio also fell (Margin Level decreased) because equity decreased.
What did not change?
- Used Margin stayed constant because we held open positions constant.
Material limitation and failure mode
A major limitation is that real-world margin systems may include additional components beyond this simplified picture, such as:
- different margin calculations by instrument,
- provider-specific rules for how and when margin is updated,
- potential effects of spreads, commissions, financing/rollover, or contract specifications.
Even if you understand Free Margin mechanically, the operational outcome can still differ because inputs and update timing are provider- and market-dependent.
Limitations, risks, and how to verify claims
What Free Margin does not guarantee
Free Margin describes availability under a margin model, but it does not guarantee that you will avoid adverse events. It can change quickly if unrealized profit/loss moves, because equity is sensitive to pricing.
Variable provider conditions
Margin terminology can be consistent in concept but different in implementation. Verification should focus on the exact definitions used by your account/provider, including:
- how used margin is computed,
- how equity is calculated (including unrealized P/L treatment), and
- how any automated limit actions are triggered (if applicable).
How you can independently verify the mechanics
You can often verify the relationship using your own account figures:
- If you know equity and used margin as displayed, compute Free Margin as equity minus used margin.
- If your platform shows a Margin Level value, compare it to equity divided by used margin to see whether it matches the displayed ratio.
If the numbers do not align with these simple formulas, that is evidence that additional rules or different definitions are in play.
Verification-oriented next question
If you want the cleanest comparison, ask for two things from your own platform documentation or account statements:
- the exact definitions of equity, used margin, Free Margin, and Margin Level used by that provider; and
- what specific changes (price moves, fees, rollover, execution updates) cause each value to update.
With those, you can explain Free Margin accurately and check whether your understanding matches the implementation without relying on prediction.