What is different about yen-quoted pairs
USD/JPY expresses how many yen are needed for one US dollar. The calculator uses a pip size of 0.01, while a third decimal place is one tenth of a pip. A move from 150.00 to 150.20 is 20 pips, rather than 200.
In the standard Forex model, one lot contains 100,000 units of the base currency: for USD/JPY, that is 100,000 USD. Multiplying by 0.01 gives 1,000 JPY per pip per lot. The result is in yen, even if the account is in dollars or euros.
Converting pip value
At a hypothetical rate of 150 JPY per USD, 1,000 JPY is worth 1,000 ÷ 150 = 6.6667 USD. For an account in EUR, you instead need the rate between yen and euros. If 1 EUR is worth 160 JPY, pip value is 1,000 ÷ 160 = 6.25 EUR.
The direction of the conversion matters: to move from yen to euros, the factor is the EUR value of 1 JPY, which is 1/160 in this example. Multiplying by 160 would give an incorrect figure despite using the same exchange rate shown on screen.
An example with an account in euros
On a balance of 10,000 EUR, 1% is 100 EUR. With a 20-pip stop and a pip value of 6.25 EUR per lot, the loss per lot is 125 EUR. Position size is 100 ÷ 125 = 0.80 lots, excluding costs and assuming the volume step allows that amount.
Entering 150.00 as the entry and 149.80 as the stop gives the same 20-pip distance in the calculator. For a sell trade, an entry of 150.00 and a stop of 150.20 produce the same quantity. The tool sizes risk; it does not decide whether the trade should be long or short.
Which exchange rate to use in a test
The daily exchange rate available in the tool is a conversion reference with a visible date. You can replace it with the broker’s rate. It is not equivalent to an intraday conversion performed by the platform.
In a backtest spanning years, applying one current exchange rate to every trade can distort historical monetary results. Separate the analysis of trades in pips or risk multiples from reconstructing the account in another currency. Check USDJPY coverage in the catalogue and document the convention you use.
