{"id":38,"date":"2026-05-21T00:32:01","date_gmt":"2026-05-21T00:32:01","guid":{"rendered":"http:\/\/docs.traderis.me\/en\/docs\/risk-percent-position-sizing\/"},"modified":"2026-06-06T04:31:06","modified_gmt":"2026-06-06T04:31:06","password":"","slug":"risk-percent-position-sizing","status":"publish","type":"docs","link":"https:\/\/docs.traderis.me\/en\/docs\/risk-percent-position-sizing\/","title":{"rendered":"Why You Should Drop Fixed Lots \u2014 Risk-Percent Position Sizing"},"content":{"rendered":"\n
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\ud83d\udccc Key Takeaway<\/p>\n\n\n\n

Fixed lots are fatally flawed \u2014 the same 0.1-lot trade can carry 15x different risk depending on your stop-loss width. Switching to risk-percent position sizing (Lot = Account \u00d7 1% \u00f7 Stop pips \u00d7 pip value) keeps every trade’s loss identical and makes compounding work automatically.<\/p>\n<\/div><\/div>\n\n\n\n

“I always trade 0.1 lots.” “I size my lots by gut feel.” Most FX beginners trade with fixed lots<\/strong> \u2014 the same lot size every time. But from a money-management standpoint, this is one of the most dangerous habits there is<\/strong>.<\/p>\n\n\n\n

This article explains why fixed lots are dangerous, and what you should use instead: risk-percent-based position sizing<\/strong> \u2014 with concrete numbers. Reading Lot Calculation Basics<\/a> and The 1% Rule<\/a> first will deepen your understanding.<\/p>\n\n\n\n

What Are Fixed Lots?<\/h2>\n\n\n\n

Fixed lots means ordering the same lot size every time, regardless of account equity or stop-loss width<\/strong>. “Always 0.1 lots” or “$5,000 account, so always 0.5 lots” are both fixed-lot approaches.<\/p>\n\n\n\n

It’s simple and easy to compute, so beginners like it \u2014 but it has a fatal flaw: the amount you lose per trade varies wildly depending on the situation<\/strong>. The essence of money management is controlling your loss amount, so a method that can’t control it defeats the entire purpose.<\/p>\n\n\n\n

Three Fatal Problems with Fixed Lots<\/h2>\n\n\n\n

Problem 1: Risk varies with stop-loss width<\/h3>\n\n\n\n

Even at the same 0.1 lots, a different stop-loss width means a completely different loss amount. For EURUSD (USD account, 0.1-lot pip value = $1):<\/p>\n\n\n\n

\n\n
Lot<\/th>Stop width<\/th>Loss<\/th>Risk on a $10,000 account<\/th><\/tr><\/thead>\n
0.1 (fixed)<\/td>10 pips<\/td>$10<\/td>0.1%<\/td><\/tr>\n
0.1 (fixed)<\/td>30 pips<\/td>$30<\/td>0.3%<\/td><\/tr>\n
0.1 (fixed)<\/td>80 pips<\/td>$80<\/td>0.8%<\/td><\/tr>\n
0.1 (fixed)<\/td>150 pips<\/td>$150<\/td>1.5%<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n\n\n

At the same “0.1 lots”, a 10-pip-stop trade and a 150-pip-stop trade carry 15x different risk<\/strong>. With fixed lots, “how much will I lose this time” jumps around every entry, and money management simply doesn’t hold together.<\/p>\n\n\n\n

Problem 2: Equity drops but lot stays \u2192 effective risk % rises<\/h3>\n\n\n\n

If you keep fixed lots while a losing streak shrinks your account, the effective risk % per trade automatically rises<\/strong>. Suppose your setup loses $100 per trade:<\/p>\n\n\n\n

\n\n
Account equity<\/th>Loss with fixed lot<\/th>Effective risk %<\/th><\/tr><\/thead>\n
$10,000<\/td>$100<\/td>1.0%<\/td><\/tr>\n
$5,000<\/td>$100<\/td>2.0%<\/td><\/tr>\n
$2,500<\/td>$100<\/td>4.0%<\/td><\/tr>\n
$1,000<\/td>$100<\/td>10.0%<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n\n\n

The more your account shrinks, the higher the risk % climbs, and Risk of Ruin<\/a> spikes. This is the worst possible behavior \u2014 “take maximum risk exactly when you’re losing.”<\/p>\n\n\n\n

Problem 3: Equity grows but lot stays \u2192 no compounding<\/h3>\n\n\n\n

Conversely, if your account grows steadily but your lot stays fixed, you can’t put the extra capital to work and you forfeit compounding<\/strong>. If your account doubles but per-trade risk is unchanged, your growth rate plateaus.<\/p>\n\n\n\n

What Is Risk-Percent Position Sizing?<\/h2>\n\n\n\n

The fix for all three problems at once is risk-percent-based position sizing<\/strong>. Instead of a fixed lot, you derive the lot from a constant risk % of account equity (e.g. 1%)<\/strong>.<\/p>\n\n\n\n

Lot = (Account equity \u00d7 Risk%) \u00f7 (Stop pips \u00d7 1-pip value)<\/strong><\/pre>\n\n\n\n
This automatically makes wide-stop trades smaller and tight-stop trades larger, so that every trade risks the same amount (e.g. 1% of the account)<\/strong>.<\/p>\n\n\n\n
At fixed 1% risk, loss stays constant regardless of stop width<\/h3>\n\n\n\n
\n\n
Account equity<\/th>Stop width<\/th>Lot<\/th>Loss<\/th>Risk %<\/th><\/tr><\/thead>\n
$10,000<\/td>10 pips<\/td>~1.0<\/td>$100<\/td>1.0%<\/td><\/tr>\n
$10,000<\/td>30 pips<\/td>~0.33<\/td>$100<\/td>1.0%<\/td><\/tr>\n
$10,000<\/td>80 pips<\/td>~0.125<\/td>$100<\/td>1.0%<\/td><\/tr>\n
$10,000<\/td>150 pips<\/td>~0.067<\/td>$100<\/td>1.0%<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n\n\n
Whether the stop is 10 pips or 150 pips, the loss is always $100 (1% of the account). The risk that varied 15x under fixed lots becomes perfectly constant<\/strong> under risk-percent sizing. This is the core of money management.<\/p>\n\n\n\n
Risk-Percent Sizing Compounds Automatically<\/h2>\n\n\n\n
Because the lot tracks account equity, risk-percent sizing makes you attack automatically when winning and defend automatically when losing<\/strong>.<\/p>\n\n\n\n
\n\n
Account equity<\/th>1% risk loss<\/th>Behavior<\/th><\/tr><\/thead>\n
$20,000 (grew)<\/td>$200<\/td>Lot scales up with equity (compounding)<\/td><\/tr>\n
$10,000<\/td>$100<\/td>Baseline<\/td><\/tr>\n
$5,000 (shrank)<\/td>$50<\/td>Lot scales down with equity (defense)<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n\n\n
Where fixed lots gave “max risk when losing, growth stalls when winning,” risk-percent sizing does the exact opposite<\/strong> \u2014 the ideal behavior.<\/p>\n\n\n\n
Why Manual Calculation Doesn’t Last<\/h2>\n\n\n\n
Risk-percent sizing is clearly superior, but the catch is that recomputing the lot every trade is tedious<\/strong>. Each entry requires checking account equity, stop pips, and the pair-specific pip value, then dividing \u2014 and doing that accurately while the market is moving isn’t realistic.<\/p>\n\n\n\n
The result is backsliding: “the math is annoying, so I’ll just enter with my usual fixed lot.” Sustaining risk-percent sizing requires automation<\/strong>.<\/p>\n\n\n\n
Automate with Auto-Lots Calculation EA (Free)<\/h3>\n\n\n\n
TraderIsMe’s free Auto-Lots Calculation EA<\/strong> is exactly the tool to automate risk-percent position sizing. Draw a stop-loss line on the chart, and it computes the right lot from “account equity \u00d7 your risk %” and places the order<\/strong>.<\/p>\n\n\n\n
Risk % is freely configurable (0.5%, 1%, 2%, …), and the EA handles pair-specific pip values and current equity internally. This frees you from “the fixed-lot temptation” and mechanically maintains consistent risk across every trade.<\/p>\n\n\n\n
For setup, see Free EAs \u2014 Common Setup Guide<\/a>. For feature details, see Auto-Lots Calculation EA Manual<\/a>.<\/p>\n\n\n\n
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Auto-Lots Calculation EA (MT5)<\/a><\/div>\n\n\n
Auto-Lots Calculation EA (MT4)<\/a><\/div>\n\n<\/div>\n\n\n\n
Summary<\/h2>\n\n\n\n