Who is it for?
Users who want to quantify risk before trading Anyone who verifies account and symbol specifications
Risk & Position Sizing
Forex Position Size & Lot Size Calculator
Calculate forex position size and lot size from account balance, risk percentage, stop-loss distance, and pip or tick value, with formula and worked example.
FreeNo installationEducational & analytical
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No account requiredForex Position Size & Lot Size Calculator
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Tool guide
What is position size and how is it calculated?
Position size is the amount traded after matching stop-loss exposure to a predefined money-risk budget. If raw size is below the broker’s minimum valid volume, the tool does not round upward into a risk-budget violation; it reports that no valid volume fits.
Logic / formula
Risk budget = equity × risk%; raw size = risk budget ÷ risk per lot/unit; final size is floored only within valid min/step/max volume rules.
Read the output
Read suggested volume with the risk budget and final-volume risk. A dash means no broker-valid volume fits the entered risk limit.
TT-FT-001 · versioned engine position-size@2.0.0 · educational/analytical use; not investment advice.
Full guide, examples, and sources
When should you not rely on it?
Guessed inputs or invalid broker specifications Using it as a profit forecast
Logic, formula and methodology
Position size is the amount traded after matching stop-loss exposure to a predefined money-risk budget. If raw size is below the broker’s minimum valid volume, the tool does not round upward into a risk-budget violation; it reports that no valid volume fits. Risk budget = equity × risk%; raw size = risk budget ÷ risk per lot/unit; final size is floored only within valid min/step/max volume rules.
Exact risk-budget sizing with direction validation, symbol conversion, optional spread/commission, manual broker overrides, floor-to-step rounding, minimum/maximum volume rules, and effective-risk output.
Worked example
Example
£10,000 account, 1% risk, EURUSD entry 1.1000 and stop 1.0950
Here the risk budget is £100; size should be floored so estimated stop loss plus modeled costs does not exceed that budget.
Here the risk budget is £100; size should be floored so estimated stop loss plus modeled costs does not exceed that budget.
How to read the result
The headline number must be read with assumptions and warnings. Out-of-bound values should be corrected before trading.
Read the position size together with risk amount, stop distance, risk per lot and volume-limit warnings. If broker step/minimum rules prevent an exact match to the risk budget, a smaller rounded-down size is the conservative outcome. Do not confuse gross price risk with cost-adjusted risk.
What the TupTrader version adds
The value of this version is not cosmetic; the result, assumptions and workflow are connected to the practical capabilities below.
- Entry-to-stop price ladder
- Risk budget meter
- Stop distance in price, pip or point units
- Gross/net risk with cost profile
- Saved trader profile
- Favorite symbols
- Broker/symbol source badge
- Copy position size
Turn the result into a workflow
Related tool →Cross-check the result with the broker or platform. Record risk in the entry checklist. Record the actual value in the journal after the trade.
Common mistakes and limitations
- Confusing risk with margin or potential profit
- Ignoring costs and rounding
- Using the wrong unit or currency
- Accuracy depends on contract size, tick/pip size, conversion rate and broker rules. Real slippage, gaps, stop execution and instrument-specific rules can change realized loss, so the result should be checked against the broker specification.
Frequently asked questions
Should I choose lot size first and move the stop to fit it?
For disciplined risk control, the stop should reflect trade invalidation and position size should adapt to that stop.
Why can the tool return slightly less volume than a hand calculation?
Because final size is floored to the allowed volume step and constrained by minimum/maximum size so rounding does not push estimated loss above budget.
Is 1% or 2% risk mandatory?
No. The risk percentage should match your account rules, risk tolerance and trading plan.
Sources and research method
This guide combines the tool’s versioned specification, the earlier TupTrader educational page and the authoritative sources below. External sources are used for definitions and scientific boundaries, not for signals.
- CME Group — Proper Position SizePosition sizing based on stop placement and the account amount or percentage at risk.
- CFTC — Eight Things You Should Know Before Trading ForexLeverage, trading costs and dealer/broker-specific conditions in OTC forex.
This tool is for education, scenario analysis and process control. It is not investment advice, a buy/sell signal or a guarantee of future performance.
Transparent calculation
Position-size formula and a complete worked example
Risk budget
Risk budget = balance or equity × risk percentage. For a USD 10,000 account at 1% risk, the planned maximum loss is USD 100.
Raw size
Raw lots = risk budget ÷ (stop distance × pip value per lot). With a 50-pip EURUSD stop and USD 10 per pip per standard lot: 100 ÷ 500 = 0.20 lots.
Units and rounding
The example assumes a USD account, USD as quote currency, and a 100,000-unit standard lot. For JPY pairs, metals, indices, and CFDs, use the broker symbol’s pip/tick value and volume step. Final size is rounded down to a valid step.
Cross-check pip value with the pip calculator, review the planned payoff in the risk/reward calculator, and record actual execution in the trading journal.
Spread, commission, slippage, gaps, and stop execution can change realized loss. Verify contract size and symbol specifications in the broker platform.