What is lot size? Understanding your trading exposure
Lot size describes the quantity traded in the platform's contract units. In common forex terminology, a standard lot represents 100,000 base-currency units, a mini lot 10,000, and a micro lot 1,000. These conventions are not universal across asset classes. OANDA explains standard, mini and micro lots.
How do I turn lots into units?
Use: lots × units per lot. If a hypothetical forex symbol specifies 100,000 units per lot, 0.25 lot represents 25,000 units. If a different symbol specifies 100 units per lot, 0.25 lot represents 25 units. The number entered in the order window is the same; the exposure is very different.
Is lot size the amount deposited?
No. A position's units, its notional value and its required margin are separate quantities. For example, 25,000 EUR at an illustrative EUR/USD price of 1.10 represents USD 27,500 of notional exposure. This calculation does not tell you the required margin or maximum possible loss.
What should I check before an order?
Read the contract size, minimum volume and volume step in the symbol specification. MetaTrader documents those fields in its Market Watch specification guide. A minimum volume is an order constraint, not a recommendation about suitable risk.
Combine position size with an adverse price scenario and the applicable costs. Continue with pip value and leverage and margin.
Educational information only. Examples exclude costs unless stated and do not describe a recommended trade or guaranteed outcome.