Margin Calculator
Modify the values and click calculate
Position Details
Required Margin
Enter your position and equity details to check margin sufficiency.
Note: this calculator refers to trading margin (leverage used to open a stock, futures, or forex position) -- not the "margin" (interest rate spread) sometimes used to describe a loan or mortgage rate.
Understanding Trading Margin
In trading, "margin" is the amount of your own cash a broker requires you to put up to open a leveraged position -- the rest of the position's value is effectively financed by the broker. This calculator converts between margin percentage and leverage ratio, tells you exactly how much cash a given position requires, and shows the maximum position size your current equity can support.
Margin % and Leverage Ratio Are Two Views of the Same Thing
A 25% margin requirement and 4:1 leverage describe the exact same relationship: leverage = 100 / margin%. If your broker quotes one, this calculator instantly converts to the other so you can compare offers stated in either convention.
Buying Power: What Your Equity Supports
Your account equity, divided by the margin requirement, tells you the maximum total position size you can open -- this is your "buying power." Higher leverage (a lower margin %) stretches the same equity into a much larger position.
Leverage Cuts Both Ways
Leverage magnifies gains and losses equally -- a 4:1 leveraged position moves roughly four times as fast, in dollar terms, as your equity would unlevered. A price move against you can trigger a margin call requiring more cash, or a forced liquidation.
Not the Same as a Loan's "Margin"
"Margin" is an overloaded term. Here, it means trading margin -- the equity you put up for a leveraged stock, futures, or forex position. It is unrelated to a mortgage or loan's "margin," which is the fixed spread a lender adds on top of an index rate.
Worked Example
Suppose you want to open a $10,000 position, your broker requires 25% margin (equivalent to 4:1 leverage), and you have $3,000 in account equity:
- Required margin: $10,000 × 25% = $2,500.
- Maximum position size supportable: $3,000 × (100 / 25) = $12,000.
- Sufficiency check: $3,000 in equity ≥ $2,500 required → Sufficient, with $500 of spare buying power.
Equity vs. Requirement
- Account equity: $3,000.00
- Required margin: $2,500.00
- Max position size: $12,000.00
Key Takeaways
-
Margin % and Leverage Are Interchangeable: Convert freely between the two using
leverage = 100 / margin%. - Buying Power Scales With Leverage: The same equity supports a much larger position at higher leverage -- but also a much larger loss.
- Check Sufficiency Before You Trade: If your equity falls short of the required margin, reduce your position size or add funds before opening the trade.
- Trading Margin, Not Loan Margin: This tool is for leveraged trading positions -- for a loan or mortgage interest rate, see our Loan or Mortgage Calculator instead.