How much should I risk?
The trade is fine. The size is what blows up accounts. This calculator turns an entry, a stop and a risk percentage into a share count, and tells you what the Kelly formula thinks of your edge.
Works in Google Sheets and Excel.
SEVEN INPUTS
Account size, risk per trade, entry, stop, target, your win rate, your average win-to-loss ratio.
WHAT COMES OUT
- Shares to buy so the stop costs exactly your risk amount
- Dollars at risk, position value, reward-to-risk
- Expected value per dollar risked
- Full Kelly and half Kelly as a share of the account
- A table of 0.5% to 5% risk per trade, with how many straight losses it takes to lose 20%
What you get
- The calculator (.xlsx, opens in Google Sheets or Excel)
- A 1-page quick-start guide
Who it's for
Swing traders, day traders, anyone who has ever bought "about 200 shares, feels right".
Good to know
- No macros, add-ons or sign-ups. Works in Google Sheets (free) and Excel 2016 or newer.
- Not financial advice. Instant download.
What's inside the download
- Position-Size-Kelly-Calculator.xlsx
- Quick-Start-Guide.pdf
Made by Matthew Busel, a one-person studio in Tuckahoe, NY. About me. Questions: support@tensorust.com.
Trading and quant
Position Size & Kelly Calculator
Google Sheets + Excel
Account, risk per trade, entry, stop and target in. Shares to buy, dollars at risk, reward-to-risk, expected value and the Kelly fraction out.
Works or I fix it. If a file doesn't open or work as described, email support@tensorust.com within 30 days and I fix it or send a working copy. All sales are final, so check the screenshots or ask first.
- Updated
- Oct 2026
- File
- ZIP, 165 KB: 1 Excel sheet, 1 PDF
- Who it's for
- Swing traders, day traders, anyone who has ever bought "about 200 shares, feels right".
One-time price in US dollars, checkout by Stripe. After paying you land on a page with your download link. Each link works for 15 minutes, and reopening that page makes fresh ones.
- Position-Size-Kelly-Calculator.zip