How Leverage and Margin Actually Work on a CFD Account
How leverage and margin work on a CFD account is one of the first things every new trader needs to understand properly, because getting it wrong is how small accounts get wiped out fast. Leverage lets you control a position much larger than your deposited capital, and margin is the slice of your account that gets locked up as a good-faith deposit while that position is open. Neither is complicated once you see the mechanics — but the maths behind margin calls and stop-outs catches people out constantly, usually at the worst possible moment.
This guide walks through the actual arithmetic, shows you where margin numbers appear on your platform, and gives you a workflow for sizing positions so leverage works for you instead of against you.
What Leverage and Margin Actually Mean
Leverage is expressed as a ratio, like 30:1 or 500:1, and it tells you how much exposure you can control per unit of your own capital. At 30:1 leverage, £1,000 of your money can control a position worth £30,000. Margin is the flip side of the same coin — it's the deposit your broker holds from your account balance while that position is open, calculated as a percentage of the full position size.
- Leverage ratio — how many times your capital your exposure can be, e.g. 30:1, 100:1, 500:1.
- Margin requirement — the percentage of position value you must hold as collateral, e.g. 3.33% at 30:1 leverage.
- Used margin — the total amount currently locked up across all your open positions.
- Free margin — equity minus used margin; this is what's available to open new trades or absorb losses.
Margin requirements vary by instrument, account type, and regulatory jurisdiction — a retail account in the UK/EU is capped differently to a professional or offshore account. For the exact margin percentages and leverage caps on any broker you're considering, check their contract specifications directly or compare them via PipTax's brokers page rather than assuming a headline ratio applies to every instrument.
The Margin Calculation, Step by Step
Margin required for a position is calculated as: Position Size (in base currency) × Margin Requirement %. Here's a worked example using round numbers.
- You open 1 standard lot (100,000 units) of a currency pair.
- The notional value at the current price is roughly £80,000 (this varies by pair and price).
- Your account leverage gives a 2% margin requirement (equivalent to 50:1).
- Margin required = £80,000 × 2% = £1,600.
That £1,600 is locked as used margin the moment you open the trade. It's returned to your free margin when you close the position — it isn't a fee, it's collateral. Profits and losses are calculated on the full £80,000 exposure, not on the £1,600 margin, which is exactly why leverage amplifies both gains and losses relative to your deposit.
| Term | What it represents |
|---|---|
| Equity | Balance plus/minus floating profit or loss |
| Used margin | Collateral locked by open positions |
| Free margin | Equity − used margin |
| Margin level | (Equity ÷ used margin) × 100% |
Margin level is the number that matters most under pressure — it's what triggers margin calls and stop-outs, covered next.
Margin Calls and Stop-Out Levels
As a losing position moves against you, your equity falls while used margin stays fixed, so your margin level drops. Brokers set two thresholds:
- Margin call level — typically around 100%, where the broker warns you (often via platform alert) that you can't open new positions and existing ones are at risk.
- Stop-out level — typically 50% or lower, where the broker automatically starts closing your open positions, usually the most unprofitable one first, to bring margin level back up.
These percentages are set by each broker and can differ significantly between providers and account types — some run stop-outs at 50%, others at 20% or 30%. Never assume; check the specific broker's terms or use PipTax's cost tool to compare how margin rules interact with real spread and swap costs on your shortlist.
The stop-out isn't optional and isn't negotiable in the moment — it's an automated system protecting the broker (and, in a roundabout way, you) from a negative balance. Relying on it as a risk management tool, however, is a bad habit: by the time it triggers, you've likely lost a large chunk of your account already.
A Practical Position-Sizing Workflow
Leverage availability is not the same as leverage you should use. A workflow that keeps margin sensible:
- Decide risk per trade first — commonly 0.5%–2% of account equity, based on your stop-loss distance, not on how much margin is available.
- Calculate position size from your stop-loss, not from maximum leverage. Position size = (Account equity × risk %) ÷ (stop-loss distance in pips × pip value).
- Check the resulting margin usage — if a properly risk-sized position uses more than roughly 20–30% of free margin, that's a signal your stop-loss is too wide or your account is undercapitalised for the instrument.
- Leave headroom for multiple open positions — correlated trades (e.g. several GBP pairs) draw down margin level together during volatility.
- Re-check margin level after adding each position — most platforms show it live; don't wait for a margin call notification to look.
This keeps leverage as a tool for capital efficiency rather than a lever for oversized bets. See cost-impact.html for how spread and swap costs compound on leveraged positions held over time.
Common Leverage and Margin Mistakes
Most margin-related account blow-ups trace back to a handful of repeated errors:
- Sizing by margin available, not by risk — using all your free margin because the platform allows it, rather than calculating from a stop-loss.
- Ignoring overnight swap accumulation — margin held for days or weeks also accrues financing costs that erode equity and margin level independently of price moves; see rates.html for how swaps are calculated.
- Confusing margin requirement with actual risk — 2% margin doesn't mean 2% risk; it means 2% collateral against 100% notional exposure.
- Not accounting for correlated positions — several trades on related instruments can all move against you simultaneously, compounding margin pressure faster than expected.
- Assuming leverage caps are universal — regulated retail leverage limits differ by region and instrument class; always confirm on the broker's own specification sheet, not from marketing pages.
Key takeaways
- Leverage lets you control a larger position than your deposited capital; margin is the collateral locked up to open that position.
- Margin required = position notional value × margin requirement percentage — profit/loss is calculated on the full notional, not the margin.
- Margin level (equity ÷ used margin × 100%) is the number that triggers margin calls and stop-outs — thresholds vary by broker.
- Size positions from your stop-loss and risk tolerance first, then check margin usage — never size to the maximum leverage available.
- Swap costs and correlated open positions both erode margin level independently of price direction.
- Confirm exact leverage caps, margin requirements, and stop-out levels with each broker's own specifications — they're not standardised.
Frequently asked questions
- What is a good leverage ratio for a beginner?
- There's no single correct ratio — what matters is how much margin your actual position sizing uses, not the maximum ratio on offer. A beginner using 500:1 leverage but sizing positions conservatively from a stop-loss can carry far less real risk than someone using 30:1 and oversizing trades.
- Can I lose more than my deposit trading CFDs on margin?
- With negative balance protection, which most retail brokers in regulated regions provide, you typically cannot lose more than your account balance. Without it, or on professional/offshore accounts, losses beyond your deposit are possible. Confirm this explicitly with any broker before trading — see /brokers/index.html for comparisons.
- What happens exactly when a stop-out is triggered?
- The broker's system automatically closes one or more open positions, usually starting with the largest floating loss, to bring your margin level back above the stop-out threshold. This happens without warning beyond the earlier margin call, and you have no control over which positions close or at what price.
- Does margin requirement change with market volatility?
- Yes, some brokers increase margin requirements during high-volatility events (major news releases, holidays with thin liquidity) as a risk control. Check the broker's specific policy rather than assuming margin stays fixed.
- Is used margin the same as risk on a trade?
- No. Used margin is collateral held against the full notional exposure — your actual risk depends on how far price can move against you before your stop-loss, multiplied by position size, which is usually a much smaller figure than the margin itself.