Lot Sizes in Forex

In forex, you do not buy "one share" of a currency. You trade a block of currency units, and that block is called a lot. The lot size sets how big your position is.

There are three standard sizes you will see almost everywhere. A standard lot is 100,000 units of the base currency. A mini lot is 10,000 units, or one tenth of a standard lot. A micro lot is 1,000 units, one tenth of a mini lot.

The base currency is the first currency in the pair. So one standard lot of EUR/USD is 100,000 euros, and one micro lot of EUR/USD is 1,000 euros. Some brokers also offer nano lots of 100 units, but the three above are the ones to learn first.

Lot size is the single biggest control you have over how much each price move is worth to you. The same chart and the same trade idea can risk a few cents or a few hundred dollars depending only on the lot you pick.

For most USD-quoted pairs like EUR/USD, a pip is worth roughly 10 USD per standard lot, 1 USD per mini lot, and 0.10 USD per micro lot. A pip is the standard small unit a price moves, the fourth decimal place for most pairs. So if EUR/USD moves 20 pips in your favour or against you, that is about 200 USD on a standard lot but only about 2 USD on a micro lot.

This is why beginners are usually pointed at micro lots. Trading is risky and most retail traders lose money, so keeping each pip small while you learn keeps a mistake cheap. The skill of sizing your risk carefully transfers to other markets too, but here the teaching is forex.

The notional value of a position is the full size of the currency you control, not the cash you put up. One standard lot of EUR/USD trading at 1.0800 has a notional value of 108,000 USD, because 100,000 euros at 1.0800 is 108,000 USD.

You do not need 108,000 USD in your account to open that trade. Leverage lets you control a large notional position with a smaller deposit, called margin. At 30 to 1 leverage, that 108,000 USD position needs about 3,600 USD of margin set aside.

Leverage cuts both ways. It does not change the notional value or the pip value. It only changes how little cash is locked up to hold the position. A bigger notional means bigger swings in your account for the same pip move, which is exactly why lot size deserves real thought before every trade.

Work backwards from how much you are willing to lose on the trade, not from how much you hope to gain. Decide your stop first. A stop is the price where you exit if the trade goes against you, and the distance from your entry to your stop is your risk in pips.

Here is a clean example. Say you are willing to risk 20 USD on a EUR/USD trade and your stop is 40 pips away. On a micro lot, each pip is about 0.10 USD, so 40 pips is about 4 USD per micro lot. To risk 20 USD, you would trade about 5 micro lots (20 divided by 4).

The order is always the same. Set the stop, know the pip value for your lot size, then size the position so the loss at your stop is an amount you have accepted in advance. Many brokers offer a position size calculator, but doing the arithmetic yourself once or twice makes the relationship stick.

The most common beginner mistake is trading too large. A standard lot on a small account can wipe out a big chunk of it in a single normal move. If a 20 pip move makes your stomach drop, your lot size is too big.

Another trap is picking a round lot size first and discovering your risk afterwards. Lot size should be the output of your risk plan, not the starting point. Choose the dollars you will risk and the stop distance first, then the lot size follows.

Finally, do not forget that pip value changes across pairs. The roughly 10 USD per pip per standard lot rule fits USD-quoted pairs. For pairs where USD is not the quote currency, or for JPY pairs which are quoted to two decimals, the pip value is different, so check it rather than assuming.