📘 How This Tool Should Be Used
This calculator is designed to help users understand how position sizing and transaction costs affect risk exposure.
It does not determine whether a trade is suitable or appropriate.
Users should independently evaluate their own financial situation before trading.
⚠️ Important Disclaimers
Please read carefully before using this tool:
- No Financial Advice: This calculator is an educational tool only and does not provide investment advice or recommendations.
- No Suitability Assessment: This tool does not assess suitability, appropriateness, or your financial circumstances.
- Arithmetic Only: This tool performs arithmetic calculations only. It does not analyse market data, trends, or probabilities.
- No Personal Data: This tool does not collect, store, or analyse personal financial data.
- Estimates Only: All calculations are estimates and may differ from your broker's actual P&L due to spreads, slippage, and live FX rates.
- No Liability: Nothing on this site tells you whether to buy, sell, or hold any security. You are solely responsible for your own trading decisions.
- Capital at Risk: Trading capital is at risk; you may lose some or all of your investment.
Regulatory Status: This website is not authorised by the Financial Conduct Authority (FCA) and does not provide regulated financial services.
No Brokerage Affiliation: This tool is not affiliated with, endorsed by, or connected to Trading212 or any broker.
⚠️ These outputs are mathematical illustrations only. They are not trade recommendations.
Mathematical Results
Calculated position size based solely on numbers you entered:
📊 Risk Level Comparison
Compare position sizes at different risk percentages (keeping entry, stop, and fees constant):
About Sizerra
Sizerra was born from a simple observation: most trading education focuses on what to trade, but very few resources teach you how much to trade.
When I started trading, I made the classic mistakes - risking too much on single positions, not accounting for broker fees, and watching small losses turn into account-damaging hits because I didn't understand position sizing maths.
I built Sizerra as the tool I wish I'd had when I was learning. It's a simple calculator to understand the mathematical relationship between your entry, your stop loss, and your capital at risk.
Why Position Sizing Matters
Successful traders often succeed because they:
- Risk consistent, manageable amounts per trade (commonly 1-2% of capital)
- Account for transaction costs in their risk calculations
- Understand how position size affects their breakeven point
- Use proper risk management to protect their accounts
Sizerra illustrates these calculations through educational examples. It shows you what happens mathematically when you change your stop distance, your position size, or your risk tolerance.
What Sizerra Does (and Doesn't Do)
Sizerra is designed for:
- Learning position sizing arithmetic and calculations
- Understanding how broker fees mathematically affect risk exposure
- Visualising hypothetical risk-reward scenarios
- Saving and comparing different educational examples
- Practising position sizing concepts in a risk-free environment
Sizerra explicitly does NOT:
- Recommend what to buy, sell, or trade
- Assess whether any trade or strategy is suitable for you
- Provide investment advice, financial guidance, or recommendations
- Guarantee accuracy, trading results, or profitability
- Replace professional financial advice or education
- Analyse your personal financial circumstances
Important Limitations & Margin for Error
Please understand these critical limitations:
- Estimates Only: All calculations are approximations. Real-world results will differ due to spreads, slippage, live market conditions, and exact broker fee structures.
- No Live Data: Sizerra does not connect to brokers or access real-time market data. FX rates are informational examples only.
- Fee Assumptions: Default fee percentages are based on publicly available broker data as of February 2026. Your actual fees may be higher or lower. Always verify with your broker.
- Market Risk: No calculator can predict or eliminate market risk. Position sizing is one tool among many for managing risk.
- Not Professional Advice: This tool cannot replace professional financial advice tailored to your specific situation.
Always verify all calculations with your broker before executing any trade.
My Mission
I believe every trader - whether beginner or experienced - deserves free, transparent tools to understand mathematical concepts in trading. Sizerra is completely free to use, with no ads, no data collection, and no hidden costs.
This is a tool I felt a lot of people starting out would have loved to have when they first began learning about trading. I hope it helps you understand position sizing as much as I wish it had helped me.
Support Sizerra
Sizerra is free and always will be. If you find it valuable and want to support continued development, you can contribute via Stripe. Every contribution helps keep this tool free and independent.
💳 Support Sizerra
Contact: Questions, feedback, or bug reports? Email me at itzatreat@gmail.com