Direct answer
A “good” lot size for a $20 forex account is one that makes each pip move small compared with the money you can risk—based on your broker’s pip value for the instrument and your position size. Because brokers can use different contract sizes and minimum lot steps, there is no single correct lot size for every $20 account.
How lot size and pip value work
In forex, a “lot” is a standardized trade unit. Your lot size directly scales the money effect of price changes: when price moves by one pip, the profit or loss is proportional to the lot size.
To connect lot size to account impact, the key concept is pip value: the amount of account currency you gain or lose per pip for a given position size. Pip value depends on several inputs that you should verify in your broker’s trading specifications:
- Contract size (how many units the broker treats as 1.00 lot)
- The pip definition for the pair (for example, how a pip is measured in price)
- Account currency vs. quote/base currency (conversion may be needed)
- Minimum lot size and lot step (how finely you can adjust your order)
Lot size selection for a small account is therefore a pip-value problem, not a fixed-number rule.
A practical way to choose a lot size (example checks)
Because no two brokers are guaranteed to give the same pip value, use a checkable method:
- Find your pip value per lot (or use the broker’s calculator). Compute what one pip costs or pays at a few lot sizes.
- Estimate how many pips could happen against you during the type of movement you are willing to tolerate. This is not a prediction; it is a scenario you choose for planning.
- Convert that scenario into an approximate worst-case loss: pip value × pips.
- Compare that loss to your usable balance (not necessarily the full $20, since margin and spreads can affect what is effectively available).
For a $20 account, this typically leads to using very small lots (often the minimum allowed by the broker), because even modest pip moves can become large relative to a small balance. If your broker’s minimum lot and step size are coarse, the smallest allowed position may be the only feasible option; if so, the “good” choice becomes the smallest lot that exists on your platform.
Relevant limitations and risks
- Broker and instrument differences: pip value can vary by pair and by broker contract specifications, so any “good for $20” answer depends on those details.
- Execution effects: spreads and possible slippage mean real outcomes may differ from a pip-value estimate.
- Margin and leverage: a small account can face margin constraints; losing trades can reduce usable balance quickly.
- Uncertainty: without your exact broker specs and live instrument settings, any lot size suggestion would be an approximation, not a dependable rule.
If you want, share the currency pair you trade and your broker’s contract size/minimum lot step, and you can use the same pip-value checks to determine a lot size that keeps pip-by-pip impact aligned with your $20 account constraints—without relying on fixed “best” numbers.