Lot is specific amount of units. Standard size for lot is 100,000 units. There are also: mini, micro and nano lot size.
Mini lot- 10,000 units
Micro lot – 1,000 units
Nano lot – 100 units
USD/JPY at an exchange rate of 119.80 (.01 / 119.80) x 100,000 = $8.34 per pip
How to calculate profit and loss?
Let say you buy Euros and sell U.S. dollars
The exchange rate is 1.4100 / 1.4103. Because you are buying Euros you will be working on the “ask” price of 1.4103, or the rate at which traders are prepared to sell. You buy 1 standard lot at 1.4103 after a while price goes up to 1.4130(read also what is forex). Difference between 1.4103 and 1.4130 is 27 pips so let do the math:
(0.0001 / 1.4130) x 100,000 = 7.07 Euro per pip
7.07 x 27 = 190.89 euros
So we make a 190.89 euro profit out from 27 pips