Forex Lot Sizes Explained
Lot size is the unit of measurement for forex position size — but brokers offer four different conventions. Here's what each means and how to convert between them.
1 standard lot = 100,000 units of base currency. 1 mini lot = 10,000. 1 micro lot = 1,000. 1 nano lot = 100.
Why lot size matters beyond just position size
Lot size scales pip value, margin requirement, and commission directly — a mini lot has exactly 1/10th the pip value, margin and per-lot commission of a standard lot on the same pair. Knowing your exact unit count keeps every other calculation accurate.
Not every broker offers every size
Standard and mini lots are near-universal; micro lots are common on retail platforms; nano lots are less common but useful for very small accounts or precise scaling. Check your broker's minimum trade size before assuming a convention is available.
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Frequently Asked Questions
Can I trade fractional lots, like 0.37 lots?↓
Most brokers support decimal lot sizes down to 0.01 (a micro lot), so 0.37 standard lots is a valid, common trade size.
How is lot size different from position sizing?↓
Lot size is the unit of measurement; position sizing is the decision of how many lots to trade based on your risk tolerance and stop-loss — see the Position Size Calculator for that calculation.