Affiliate disclosure: Brokelio may receive a commission linked to the activity of clients registered through this link, under the Exness partner programme.
Choosing position size before entry makes the scenario’s cash impact visible. Volume becomes a consequence of the plan. This guide explains educational arithmetic; your risk budget should reflect your capital and trading plan.
Calculate size from invalidation
Start with the level that invalidates the idea. Measure its distance from entry in a consistent unit. Obtain that unit’s value at one lot, converted into account currency where necessary. Platform points, pips and price units are not interchangeable.
Simplified formula before costs: lots = theoretical loss budget ÷ (stop distance × value per movement unit at one lot). It assumes a linear relationship for the contract. It does not replace symbol specifications or execution rules.
A complete sizing example
Fictional assumptions: USD 100 theoretical budget, a 40-point distance and USD 2 per point at one lot. The result is 100 ÷ (40 × 2) = 1.25 lots. These amounts and volumes are not recommendations.
| Assumption | Calculation | Result |
|---|---|---|
| No separate costs | 100 ÷ 80 | 1.25 lots |
| Estimated costs of USD 4 per lot | 100 ÷ (80 + 4) | About 1.1905 lots |
| Fictional 0.01-lot increment | Round down | 1.19 lots |
| Check the second plan | 1.19 × 84 | USD 99.96 estimated |
The USD 4 cost is invented and assumed proportional to volume. Minimum commissions, conversions or spread already included require model adjustments. Actual increments and permitted sizes come from the symbol, not this table.
Check margin separately
Planned loss at the stop and required margin are different quantities. Check available margin after existing positions. Leverage can change dynamic requirements without reducing loss at the same volume and price move.
The Exness calculator uses account, currency, instrument, volume and leverage. Estimated charges can differ from real execution. Review actual order and contract settings too; an estimate does not establish that the platform will accept the exact plan.
When the calculation does not fit permitted volume
Rounding up may exceed the planned budget. If the contract minimum is too large, that contract cannot reproduce the calculated sizing. Moving invalidation solely to make volume acceptable changes the original setup.
Recalculate distance and volume if entry changes. Do not keep a result based on an old price as if it remained exact. Correlated positions and overnight costs also need a combined assessment.
Benefits and limits of the formula
It connects lot size with a planned amount and defined invalidation. Its limitation is estimation: slippage, rapid moves or different settings can increase actual losses. A requested stop does not guarantee execution at the exact price.
Frequently asked questions
How much capital is needed for one lot?
There is no single answer: contract, stop, charges, margin and existing exposure matter.
Can I copy another trader’s lot size?
Identical volume does not create identical relative exposure with different capital or contracts.
Should I choose volume before the stop?
This calculation starts with invalidation. Choosing volume first does not quantify the planned loss.
Why we recommend Exness for trade preparation
Exness is our preferred choice for comparing accounts and examining volume, margin and charges through its documentation and calculator. The tool does not select a strategy or guarantee an outcome. Check your country’s offer and account specifications.
Explore Exness account types to distinguish cost structures. Open an Exness account through our partner link if you wish to open an account. Brokelio may receive commissions under the partner programme.
Sources and method
Official sources checked on 9 October 2026. Original calculations and fictional examples, with no instrument selected or personal performance claimed. Live parameters depend on contract, account and execution conditions. CFD trading can result in loss of capital.