What 1 pip is on AUDUSD
A lot of AUD/USD is 100,000 Australian dollars priced in US dollars, so a 0.0001 move is worth $10 per lot at any price, as on every pair quoted in dollars.
The pair trades lower than EUR/USD (around 0.66), so 1.00 lot is only about $66,000 of notional: the margin per lot is about half that of GBP/USD while the risk per pip is the same. MetaTrader shows 5 digits (0.66123): 1 pip = 10 points, tick size 0.00001.
AUDUSD pip value per lot
Value of one pip (0.0001 in price): 0.0001 × 100,000 = $10 per 1.00 lot.
| Position | 1 pip | 15 pips (0.0015) |
|---|---|---|
| 1.00 lot | $10.00 | $150.00 |
| 0.10 lot | $1.00 | $15.00 |
| 0.01 lot | $0.10 | $1.50 |
Worked example: 1% of $10,000
- Risk: 1% × $10,000 = $100.00.
- Stop: 15 pips = 0.0015 in price.
- Value of 1 pip per 1.00 lot: $10.00.
- Lot size = $100.00 ÷ (15 × $10.00) = 0.6667, rounded down to the 0.01 step: 0.66 lots.
The exact size, 0.6667 lots, isn't a multiple of the 0.01 volume step. Rounding down to 0.66 keeps the loss at the stop just under $100.
Contract size and tick value in MT5
In MetaTrader 5, right-click AUDUSD in Market Watch and choose Specification: it shows Contract size, Digits, Profit currency and the volume limits. Tick size and tick value are what MQL5 reads with SYMBOL_TRADE_TICK_SIZE and SYMBOL_TRADE_TICK_VALUE; the script below prints them for your account.
| Contract size | 100,000 AUD |
|---|---|
| Digits | 5 (e.g. 1.16253) at most brokers |
| Tick size (SYMBOL_TRADE_TICK_SIZE) | 0.00001 |
| 1 pip | 0.0001 = 10 ticks (10 MT5 points) |
| Profit currency | USD |
| Tick value, 1.00 lot (SYMBOL_TRADE_TICK_VALUE) | $1.00 in a USD account |
| Volume step | Shown in Specification; 0.01 at most retail brokers |
MQL5: lot size from a money risk
A script that sends no order: it reads the contract size, tick size, tick value and volume limits your broker sets for AUDUSD, then prints the lot size that risks 1% of the balance at the stop. The stop is a price distance (0.0015), so the result is the same on 2-, 3- or 5-digit quotes. Save it as MQL5/Scripts/LotSize_AUDUSD.mq5 and compile it in MetaEditor (F7): 0 errors, 0 warnings.
//+------------------------------------------------------------------+
//| LotSize_AUDUSD.mq5 |
//| Lot size that risks a % of the balance at a given stop distance|
//+------------------------------------------------------------------+
#property script_show_inputs
input string InpSymbol = "AUDUSD"; // Symbol, exactly as in Market Watch
input double InpRiskPercent = 1.0; // Risk per trade, % of balance
input double InpStopDistance = 0.0015; // Stop-loss distance in price (0.0015 = 15 pips)
// Lots that lose about riskMoney at the stop, rounded down to the volume step.
// Returns 0 when even the minimum volume would risk more than riskMoney.
double LotsForRisk(const string symbol, const double riskMoney, const double stopDistance)
{
double tickSize = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_SIZE);
double tickValue = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_VALUE); // 1.00 lot, one tick, account currency
double step = SymbolInfoDouble(symbol, SYMBOL_VOLUME_STEP);
double minLot = SymbolInfoDouble(symbol, SYMBOL_VOLUME_MIN);
double maxLot = SymbolInfoDouble(symbol, SYMBOL_VOLUME_MAX);
if(tickSize <= 0.0 || tickValue <= 0.0 || step <= 0.0 || stopDistance <= 0.0)
return 0.0;
double lossPerLot = stopDistance / tickSize * tickValue; // money lost by 1.00 lot at the stop
double lots = MathFloor(riskMoney / lossPerLot / step + 1e-9) * step;
if(lots < minLot)
return 0.0;
int volumeDigits = (int)MathMax(0.0, MathCeil(-MathLog10(step) - 1e-9));
return NormalizeDouble(MathMin(lots, maxLot), volumeDigits);
}
void OnStart()
{
if(!SymbolSelect(InpSymbol, true))
{
PrintFormat("%s not found: use the exact name from Market Watch (some brokers add a suffix)", InpSymbol);
return;
}
int digits = (int)SymbolInfoInteger(InpSymbol, SYMBOL_DIGITS);
double point = SymbolInfoDouble(InpSymbol, SYMBOL_POINT);
double contract = SymbolInfoDouble(InpSymbol, SYMBOL_TRADE_CONTRACT_SIZE);
double tickSize = SymbolInfoDouble(InpSymbol, SYMBOL_TRADE_TICK_SIZE);
double tickVal = SymbolInfoDouble(InpSymbol, SYMBOL_TRADE_TICK_VALUE);
string currency = AccountInfoString(ACCOUNT_CURRENCY);
double risk = AccountInfoDouble(ACCOUNT_BALANCE) * InpRiskPercent / 100.0;
double lots = LotsForRisk(InpSymbol, risk, InpStopDistance);
PrintFormat("%s: contract size %g, %d digits, tick size %s, tick value %g %s per lot",
InpSymbol, contract, digits, DoubleToString(tickSize, digits), tickVal, currency);
PrintFormat("Stop %s = %.0f points. Risk %.2f %s",
DoubleToString(InpStopDistance, digits), InpStopDistance / point, risk, currency);
if(lots > 0.0)
PrintFormat("Lot size: %g", lots);
else
Print("Even the minimum volume risks more than that: widen the risk or tighten the stop");
}
The key line is stopDistance / tickSize * tickValue: the money one lot loses at the stop, already converted to your account currency by the terminal. Dividing the risk by it and flooring to SYMBOL_VOLUME_STEP gives the volume to pass to CTrade::Buy() or CTrade::Sell().
Pine Script v6 equivalent
The same sizing on a TradingView chart, from syminfo.pointvalue (money per 1.0 of price per unit) and syminfo.mintick (the chart's tick). Checked by Edgoro Pine Check; paste it into TradingView's Pine Editor to add it to a chart.
//@version=6
indicator("AUDUSD lot size for a money risk", overlay = true)
riskMoney = input.float(100.0, "Risk per trade (account currency)", minval = 0.01)
accountCcy = input.string("USD", "Account currency")
stopDistance = input.float(0.0015, "Stop-loss distance (price)", minval = 0.0)
contractSize = input.float(100000.0, "Units per 1.00 lot at your broker", minval = 0.0)
// One unit of the symbol gains or loses syminfo.pointvalue (in syminfo.currency) per 1.0 of price
fx = request.currency_rate(syminfo.currency, accountCcy)
lossPerUnit = stopDistance * syminfo.pointvalue * fx
units = lossPerUnit > 0 ? riskMoney / lossPerUnit : na
lots = contractSize > 0 ? math.floor(units / contractSize * 100) / 100 : na
var table info = table.new(position.top_right, 2, 3, bgcolor = color.new(color.gray, 80))
if barstate.islast
table.cell(info, 0, 0, "Stop")
table.cell(info, 1, 0, str.tostring(stopDistance / syminfo.mintick, "#") + " ticks of " + str.tostring(syminfo.mintick))
table.cell(info, 0, 1, "Units")
table.cell(info, 1, 1, str.tostring(units, "#.####"))
table.cell(info, 0, 2, "Lots (rounded down)")
table.cell(info, 1, 2, str.tostring(lots, "#.##"))
On a TradingView forex chart, syminfo.pointvalue is 1: units is an amount of AUD, and 100,000 of them make a lot. request.currency_rate() converts the USD result into your account currency.
Common mistakes on AUDUSD
- Rounding 0.666 up to 0.67. Rounding to the nearest step adds risk: 0.67 lots × 15 pips × $10 = $100.50. Floor to the volume step instead, as the code below does.
- Lower margin, same risk. The small notional lets you open larger sizes on the same margin. The stop distance, not the margin, decides how much a trade can lose.
- Two Antipodean pairs at once. AUD/USD and NZD/USD tend to move together: 1% on each is closer to one 2% bet than to two independent ones.
Lot size sets how much a trade loses if the stop is hit at its price. It doesn't make a trade a good one, and gaps or slippage can make the loss larger. Trading involves substantial risk of loss and is not suitable for every investor. Edgoro is a software tool, not a broker or financial adviser: nothing it produces is investment advice, and past or backtested performance does not guarantee future results.