“One lot” means wildly different amounts of money depending on which lot you mean — and mixing them up is how a position that felt “small” quietly breaks a challenge.
What a lot actually is
A lot is the unit forex brokers use to size a position. Currencies move in fractions of a cent, so trading a single euro or dollar would be meaningless — the profit on a normal move wouldn’t cover the spread. A lot bundles a fixed quantity of the base currency (the first currency in the pair) into one tradable block.
The anchor everything hangs off is this: 1 standard lot = 100,000 units of the base currency. On EUR/USD, one standard lot controls 100,000 euros’ worth of exposure. Every other lot size is just a fraction of that number. Your leverage and margin then determine how little cash you actually post to hold it — but the exposure is set by the lot.
Standard, mini, micro and nano
There are four common sizes, each a step of 10× smaller than the last:
| Lot | Base-currency units | Broker notation |
|---|---|---|
| Standard | 100,000 | 1.0 |
| Mini | 10,000 | 0.1 |
| Micro | 1,000 | 0.01 |
| Nano | 100 | 0.001 |
Micro (0.01) is the granularity most funded traders actually work in, because it lets you tune size finely around a fixed dollar risk. Nano isn’t offered everywhere — treat it as broker-specific and confirm it exists before you build a plan around it. When you type 0.34 into an order ticket, you’re just saying “34 micro lots,” or equivalently a third of a standard lot.
How lot size sets your pip value
Lot size matters because it fixes your pip value — how much one pip of movement is worth in cash. For a pair quoted in USD (anything XXX/USD), the round numbers are easy to remember:
- Standard lot → ~$10 per pip
- Mini lot → ~$1 per pip
- Micro lot → ~$0.10 per pip
So a 20-pip move on a mini lot is about $20. The same move on a standard lot is about $200. Nothing changed about the market — only the size of your slice of it.
Two caveats worth internalizing:
- When USD is not the quote currency (e.g. USD/JPY, or a cross like EUR/GBP), pip value has to be converted through the quote currency, so it drifts off the clean $10/$1/$0.10 figures.
- Metals and indices that trade in “lots” on an MT5-style platform use their own contract sizes, so don’t assume the forex numbers carry over. Check the symbol’s specification in your platform.
Choose a lot size from your risk, not your gut
The mistake that ends challenges is picking a lot size that “feels right” and discovering the dollar risk only after the stop hits. Run the math the other way around:
- Decide the dollars you’re willing to lose on the trade (a fixed fraction of your account).
- Measure your stop distance in pips.
- Solve for lot size:
lots = risk$ ÷ (stop pips × pip value per lot).
A wider stop forces a smaller lot to keep the same dollar risk; a tighter stop lets you size up. That’s the whole discipline — the lot floats so the risk stays constant. The lot size calculator does this conversion directly, and the broader position size calculator folds in account size and risk percentage so you’re not doing it in your head mid-setup.
This is also where a platform earns its keep. Shibiki logs the size, stop, and resulting dollar risk of every trade automatically as you go, so your live edge health is computed from what you actually did — not what you meant to do. And because prop firms care intensely about position sizing, you can push a hard per-trade size limit down to the broker so an over-sized order is rejected before it fills, rather than caught in a post-mortem. If you trade with a firm like FundingPips, confirm their exact lot and exposure rules directly — they differ by firm and change over time.
Lots vs futures contracts
If you also trade funded futures, notice the vocabulary doesn’t transfer. Futures don’t use lots at all — you trade a whole number of contracts, and each contract has a fixed tick value rather than a pip value. You can’t hold 0.34 of an ES contract; the smallest unit is one contract (or one micro contract, where the exchange offers a smaller version). So “size” in futures is a discrete count, while forex lot sizing is a continuous dial you turn to hit a dollar target. Same goal — control the money at risk — two different levers.
Get the unit right first, size from your risk second, and let the platform enforce it. That order is what keeps a “small” trade from becoming a big problem.
Related: Lot size calculator · Position size calculator · MT5 integration