67 lines
3.3 KiB
MQL5
67 lines
3.3 KiB
MQL5
 | //+------------------------------------------------------------------+
| ||
//| LotByRisk.mq5 |
| |||
//| Copyright 2026, bandersoft |
| |||
//| https://www.mql5.com/en/users/fats |
| |||
//+------------------------------------------------------------------+
| |||
//| |
| |||
//| Position sizing from a risk percentage - the thing the library |
| |||
//| is most often wanted for. |
| |||
//| |
| |||
//| Run it on any chart. It places no orders. |
| |||
//| |
| |||
//+------------------------------------------------------------------+
| |||
#property copyright "Copyright 2026, bandersoft"
| |||
#property link "https://www.mql5.com/en/users/fats"
| |||
#property version "1.00"
| |||
#property script_show_inputs
| |||
#property description "Calculates lot size for a given risk percentage and stop distance."
| |||
| |||
#include <StopFirst\StopFirst.mqh>
| |||
| |||
input double RiskPercent = 1.0; // Risk per trade, % of balance
| |||
input double StopLossPips = 30.0; // Stop distance in pips
| |||
| |||
//+------------------------------------------------------------------+
| |||
//| Script program start function |
| |||
//+------------------------------------------------------------------+
| |||
void OnStart()
| |||
{
| |||
//--- The pip rule is the forex convention. Instruments where a pip
| |||
//--- means something else need telling, or every number below is
| |||
//--- wrong by the same factor:
| |||
//--- SetPipSize("XAUUSD", 0.1);
| |||
double pip = GetPipSize();
| |||
| |||
double lots = CalcLotSizeByRisk(RiskPercent, StopLossPips);
| |||
| |||
if(lots <= 0)
| |||
{
| |||
//--- 0 is deliberate, not a glitch: the risk budget does not
| |||
//--- cover one minimum lot. Rounding up would risk more than
| |||
//--- was asked for, so the library refuses instead.
| |||
PrintFormat("Cannot size a trade risking %.2f%% over %.1f pips on %s.",
| |||
RiskPercent, StopLossPips, _Symbol);
| |||
PrintFormat("Minimum lot is %.2f, which needs a wider stop or a larger balance.",
| |||
SymbolInfoDouble(_Symbol, SYMBOL_VOLUME_MIN));
| |||
return;
| |||
}
| |||
| |||
double risked = CalcValueAtRisk(lots, StopLossPips);
| |||
double stopDistance = PipsToPrice(StopLossPips);
| |||
double entry = SymbolInfoDouble(_Symbol, SYMBOL_ASK);
| |||
| |||
PrintFormat("%s 1 pip = %s balance %.2f %s",
| |||
_Symbol, DoubleToString(pip, _Digits),
| |||
AccountInfoDouble(ACCOUNT_BALANCE),
| |||
AccountInfoString(ACCOUNT_CURRENCY));
| |||
PrintFormat("Risking %.2f%% over a %.1f pip stop:", RiskPercent, StopLossPips);
| |||
PrintFormat(" lot size %.2f", lots);
| |||
PrintFormat(" money at risk %.2f %s", risked, AccountInfoString(ACCOUNT_CURRENCY));
| |||
PrintFormat(" buy at %s", FormatPrice(entry));
| |||
PrintFormat(" stop at %s", FormatPrice(entry - stopDistance));
| |||
PrintFormat(" reward:risk 1:%.2f at a %.1f pip target",
| |||
CalcRiskRewardRatio(entry, entry - stopDistance,
| |||
entry + stopDistance * 2),
| |||
StopLossPips * 2);
| |||
}
| |||
//+------------------------------------------------------------------+
|