Tools
Margin Calculator — how much margin do I need?
Estimate required margin, free margin, and effective leverage from position size, your broker's margin requirement %, and account equity. For planning only — not financial advice.
Quick answer
Margin is collateral for a leveraged position. With 10:1 leverage, roughly $1,000 margin controls $10,000 notional: Required margin ≈ Position ÷ Leverage. Alternatively, Required = Position × (Margin % ÷ 100). Higher leverage means less margin posted but faster loss of equity if the market moves against you.
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Definition
Required margin = Position size × (Margin requirement % ÷ 100)
Same as: Position ÷ Leverage when leverage = 100 ÷ Margin %.
Result
Enter values and tap “Calculate margin”.
When should you use a margin calculator?
- •Checking whether you have enough equity for a planned position
- •Seeing how much notional exposure you have vs. your account
- •Sizing positions within initial margin limits (simplified model)
- •Estimating free margin left after a trade to avoid surprise stress
How it works
- 1
Enter position
Total dollar value of the position you want to open.
- 2
Set requirement
Your broker’s initial margin % (e.g. 50% for a simple stock model).
- 3
See results
Required margin, free margin, and leverage vs. account and vs. posted margin.
Example
Scenario: Buy $20,000 of stock with 50% margin on a $15,000 account.
Calculation: Required margin = $10,000. Free margin = $5,000. Effective notional vs account = $20,000 ÷ $15,000 ≈ 1.33x.
Result: A 10% adverse move on the full $20,000 position ≈ $2,000 P/L — about 13.3% of the $15,000 account (illustrative; excludes fees, interest, and exact broker rules).
Frequently asked questions
Margin is collateral your broker holds so you can control a larger position than your cash alone. You borrow the rest (for stocks) or post variation margin (futures/FX). If losses erode your equity below maintenance levels, you can face a margin call or liquidation.
Related tools
Quick reference table
Illustrative: margin = position ÷ leverage; % of a $10,000 account.
| Position | Leverage | Margin required | % of $10k account |
|---|---|---|---|
| $10,000.00 | 2:1 | $5,000.00 | 50% |
| $10,000.00 | 5:1 | $2,000.00 | 20% |
| $10,000.00 | 10:1 | $1,000.00 | 10% |
| $50,000.00 | 20:1 | $2,500.00 | 25% |
| $100,000.00 | 50:1 | $2,000.00 | 20% |
US stock margin under Reg T is often summarized as up to 2:1 overnight for many equity positions. Forex in the US is subject to different limits (e.g. major pairs often capped around 50:1 for retail). Always confirm with your broker.
Related guides
Margin account vs cash account: key differences →
Read our blog for more on margin, leverage, and risk.
Last updated: April 2026
FX13: AI Trading Signals provides free trading tools, calculators, and educational resources for active traders and investors. This page is not personalized investment advice. © 2026 Rakhimboy Rozmetov. FX13: AI Trading Signals
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