Forex
Forex Lot Sizes: Standard, Mini and Micro
By MarketsBench · Published · 4 min read
Step 2 of 4 in Forex Essentials.
A "lot" in forex is just a named quantity of the base currency. The names hide the fact that there is nothing special about them — they are round numbers a broker chose, and the only figure that matters is the unit count behind each.
The four sizes
| Lot type | Units of base currency | Pip value (USD-quoted pair) |
|---|---|---|
| Standard | 100,000 | $10.00 |
| Mini | 10,000 | $1.00 |
| Micro | 1,000 | $0.10 |
| Nano | 100 | $0.01 |
Each step down is a factor of ten. Brokers usually quote sizes in decimals of a standard lot, so 0.1 lots is a mini, 0.01 lots is a micro, and 0.35 lots is 35,000 units — worth $3.50 per pip on a USD-quoted pair.
Nano lots are offered by only a handful of brokers, but they are genuinely useful for testing a strategy live with real execution and negligible money at stake.
Lot size is an output, not a decision
The order of operations traders get wrong: choosing a lot size, then finding a stop that fits it. It runs the other way.
Units = risk amount ÷ (stop in pips × pip value per unit)
A $5,000 account risking 1% has $50 at stake. With a 40-pip stop on a USD-quoted pair, each unit risks 40 × $0.0001 = $0.004:
$50 ÷ $0.004 = 12,500 units = 0.125 lots
Most brokers round to two decimals, so you trade 0.12 lots and the real risk is $48. Round down, never up.
Change only the stop and watch the size respond:
| Stop distance | Units | Lots | Actual risk |
|---|---|---|---|
| 20 pips | 25,000 | 0.25 | $50 |
| 40 pips | 12,500 | 0.12 | $48 |
| 80 pips | 6,250 | 0.06 | $48 |
| 150 pips | 3,333 | 0.03 | $45 |
The risk stays flat at roughly $50 across all four. That is the entire point: the lot size absorbs the difference so your exposure does not.
Why small accounts need micro lots
Rounding is not a rounding error on a small account — it is the whole trade.
A $500 account risking 1% has $5 to lose. With a 50-pip stop:
$5 ÷ (50 × $0.0001) = 1,000 units = one micro lot
Exactly one micro lot, with nothing to spare. On a broker offering only mini lots, the smallest available trade is 10,000 units, which risks $50 — 10% of the account on a single trade.
This is why "what lot size can I trade" is really a question about account size:
| Account | 1% risk | Smallest sensible lot with a 50-pip stop |
|---|---|---|
| $500 | $5 | 1 micro (0.01) |
| $2,000 | $20 | 4 micro (0.04) |
| $10,000 | $100 | 2 mini (0.20) |
| $50,000 | $500 | 1 standard (1.00) |
If your broker's minimum size forces you above your risk budget, the answer is a different broker or a larger account — not a tighter stop.
Lot size and margin are unrelated to risk
Trading one standard lot at 1:100 leverage requires about $1,100 of margin on a pair trading at 1.10. That figure tells you what is locked up, not what you can lose.
Your risk is the stop distance times the pip value: a 40-pip stop on that standard lot risks $400 regardless of whether the broker asked for $1,100 or $220 in margin. Leverage changes the capital efficiency of the position. It does not change the loss.
Practical notes
- JPY pairs size differently. At $6.67 per pip per standard lot instead of $10, the same risk budget buys a roughly 50% larger position. Always pull the actual pip value rather than assuming $10.
- Check the broker's minimum increment. Some allow 0.01 lots, some 0.1. It determines how precisely you can hit your risk target.
- Watch the notional, not just the risk. 0.5 standard lots on a $2,000 account is $55,000 of notional exposure. The stop caps the loss under normal conditions, but a weekend gap does not respect stops.