Position sizing is how you decide the number of lots to trade so that a loss costs only what you intended — usually a small percentage of your account. It's the practical half of risk management: a stop loss defines where you exit, and position sizing makes sure that exit only costs your planned risk. Here's the method. None of this is financial advice.
What position sizing is
Two traders can take the same trade with the same stop loss and have completely different outcomes — because one risked 1% and the other, by trading too many lots, risked 5%. Position sizing removes that guesswork: you work backwards from the money you're willing to lose to the lot size that delivers exactly that risk.
The method, step by step
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Decide your risk per trade in money
Take your risk rule — say 1% of the account — and turn it into a money figure. On a $5,000 account, 1% is $50. That's the most you'll lose if the stop is hit.
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Find the pip value for the pair and lot size
Pip value depends on the pair and your account currency. For most USD-quoted pairs it's about $10 per pip per standard lot ($1 for a mini lot). The pip calculator confirms it for your pair.
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Divide to get your position size
Position size (lots) = risk ÷ (stop pips × pip value per lot). Round down to a size your broker allows, never up. The lot size calculator does this instantly.
A worked example
Say you have a $5,000 account and risk 1% ($50) per trade. You want to trade EUR/USD with a 20-pip stop, where one pip is worth about $10 per standard lot. Your size is:
$50 ÷ (20 pips × $10) = 0.25 lots
So a quarter of a standard lot keeps your loss to $50 if the stop is hit. Widen the stop and the size shrinks; tighten it and the size grows — the risk stays fixed at $50 either way. That's the whole point.
This is a hypothetical illustration, not a prediction or advice. Pip values vary by pair and account currency, so confirm them with the pip calculator, and remember most retail traders lose money. Sizing controls risk; it doesn't create profit.
Let the calculator size it for you
The lot size calculator turns your account, risk percentage, and stop distance into a position size in seconds. Practise the workflow on a free MT4 demo first.
⚠ Trading forex and CFDs is high-risk and most retail traders lose money. This is not financial advice.
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Keep learning
Position sizing is one piece of risk management — also read about building a trading plan and trading psychology. Tools: lot size, pip value, and risk-reward.
Frequently asked questions
What is position sizing in forex?
Position sizing is deciding how many lots to trade so that, if your stop loss is hit, you lose only your intended risk — typically a small percentage of your account. It links your risk rule to an actual trade size, instead of trading a 'gut feel' number of lots.
How do I calculate position size?
Divide your risk in money by your stop distance times the pip value per lot: lots = risk ÷ (stop pips × pip value). For example, $50 of risk with a 20-pip stop on a pair worth $10/pip per lot gives 50 ÷ (20 × 10) = 0.25 lots. A lot size calculator does it for you.
Why is position sizing so important?
Because it's what actually controls your risk. You can have a great stop loss, but if the position is too big, a normal loss becomes a damaging one. Correct sizing keeps every loss to the small, planned amount — the core of staying in the game.
Should I round position size up or down?
Down. Rounding down keeps your risk at or below your intended amount; rounding up pushes it over. With small accounts you may need to accept a slightly smaller risk than planned rather than exceed it.
Does a bigger account mean bigger position sizes?
Proportionally, yes — the same percent risk on a larger balance is more money, which supports more lots for the same stop distance. The method is identical; only the dollar risk changes. Always size from your current balance, not your starting one.
Trading foreign exchange and contracts for difference (CFDs) carries a high level of risk and may not be suitable for all investors. Leverage can work against you as well as for you. You could lose some or all of your deposited funds; do not trade with money you cannot afford to lose. Past performance is not indicative of future results. Nothing on MT4Download.com is financial, investment, or trading advice. Consider your circumstances and seek independent advice if needed.