Calculator GuidesTrading — Buy
How to Use the Percentage Risk Calculator
← Back to the Percentage Risk Calculator
What this calculator actually helps you understand
The Percentage Risk calculator exists for investors who want to keep risk as % of equity. It turns that decision into a repeatable checklist instead of a guess. It works best when account value reliable and updated. Rather than promising outperformance, it helps you surface the trade-offs described as “Explain compounding effect of risk % on drawdowns.”
Inputs explained (with realistic examples)
- Account size or risk capital: How much capital you are willing to size from. Use current equity, not a rounded number from memory.
- Risk per trade: Either a fixed cash amount or a percentage of equity that you can afford to lose if the stop is hit.
- Entry and stop levels: Your planned fill price and the level where you will exit if wrong. Both should factor in slippage and volatility.
Outputs: how to read the results
- Recommended position size: How many units you can hold while respecting the risk cap.
- Cash at risk: The loss you accept if the stop executes as planned.
- What it does not do: Guarantee returns or outcomes. It simply applies the assumption "Account value reliable and updated" to your inputs.
Common mistakes people make
- Applying % to gross exposure instead of loss-at-stop.
- Treating the output as a forecast instead of a scenario.
- Ignoring fees, taxes, or behavior changes that sit outside the model.
When this calculator is genuinely useful
- When you need a calm way to keep risk as % of equity without hand-waving.
- When you want to communicate the rationale behind percentage risk decisions to a partner, advisor, or investment committee.
- When you need to compare multiple scenarios quickly (best/middle/worst).
When this calculator can mislead you
- When the core assumption (“Account value reliable and updated”) clearly does not hold in your situation.
- When inputs are based on optimistic guesses rather than verifiable numbers.
- When behavioral factors (sticking with contributions, honoring stops, etc.) matter more than the math.
How this fits into a broader financial decision
Percentage Risk is one slice of the decision. Pair it with qualitative checks: liquidity needs, tax context, counterparties, and diversification. Link it with companion calculators (for example: Explain compounding effect of risk % on drawdowns) so readers see how today’s choice affects the rest of the plan.
Use the calculator
Rules
- Do not treat any scenario as personalized advice.
- Stay conservative with inputs and double-check assumptions before acting.
- Avoid country-specific tax or regulatory claims unless you verify them yourself.