Position Sizer

Risk Command Center · size every trade before you click Buy

🎯 Backtester Sizer 🎓 Execution Lab ← Academy
Shares: risk lives between your entry and your stop.
① Your Trade
What it is: the ticker you're sizing. Optional for the math, required if you push the plan to the Execution Lab.
Why it matters: this is the denominator of the 1% Rule. Your last-used account and risk % are remembered on this device.
The rule: professionals risk ≤ 1% per trade. Ten straight losses at 1% ≈ −9.6% — fully recoverable. At 5% you'd be down ~40% — game over.
What it is: where your order fills. Use a limit at support (long) or resistance (short) — not a market order at any old price.
What it is: your protective floor. Place it beyond structure (below a swing low for longs) so normal noise doesn't stop you out.
Rule: target distance should be ≥ 3× stop distance — the 3:1 Reward-to-Risk minimum.
⚙️ Advanced — fees & slippage (default 0)
Commission + regulatory fees for ONE side (entry or exit). Charged twice — in and out. Folded into risk, profit and R:R.
Expected slippage in basis points per side (10 bps = 0.10%). Widens your effective risk and shaves your effective reward.
② Your Sizing Plan
⏳ WAITING
Enter your levels on the left — the plan updates live.
Beyond the ticket
📊 % of Account
—
Position cost as a share of your account.
📈 % Return on Account
—
Profit at target ÷ account balance.
🎯 Break-even Win Rate
—
Win more often than this and you're profitable.
Sends this sized plan to your Execution Lab Inbox so you can drill it end-to-end.
📚 How the Math Works — Live, Line by Line
Risk Budget = Account × Risk%
—
Why 1%? Ten straight losses ≈ −9.6% — recoverable. This is the 1% Rule.
Risk / Share = |Entry − Stop| + slippage
—
The distance price must move against you before the stop fires, padded by expected slippage.
Shares = ⌊ (Budget − fees) ÷ Risk/Share ⌋
—
Why floor? Rounding up would push risk past the cap. Always round down.
$ at Risk = Shares × Risk/Share + fees
—
Your real loss if the stop hits. Must be ≤ the budget.
Profit = Shares × (|Target − Entry| − slip) − fees
—
Ceiling profit if the target fills first.
R:R = Profit ÷ $ at Risk
—
The gate. At 3:1 you only need a 25% win rate to break even.
Position Sizer · Mission Metrics Impact Trading Academy · The S.E.T. Rule + the 1% Rule, enforced by arithmetic. Education only — not financial advice.