Kelly Stake Sizer
Turn your edge into the mathematically optimal stake — then take a safer slice of it.
Account balance
$
Win rate
%
Payout
%
Confidence in that win rate
Fewer than 200 logged trades? Keep this at 50-70%. Kelly punishes an overstated win rate hard.%
How much Kelly to use
Full Kelly
9.06%
of balance per trade
Your stake
$11.32
2.26% of balance
Edge per trade
7.70%
after confidence haircut
Growth captured
44%
of full-Kelly compounding
Growth vs stake size
Peak sits at full Kelly
0.39%
-0.22%
0% stake20% stake
Notice the curve falls off a cliff past the peak. Staking more than full Kelly grows the account slower and blows it up faster, which is the exact trap most traders walk into.
Projected balance over 100 trades
$589
$493
NowTrade 100
Trades to project
Sensible sizing
Full Kelly maximises long-run growth but routinely produces 50% drawdowns. At your chosen fraction it takes about 31 losses in a row to halve the account. Most traders sit at quarter Kelly, keep roughly 44% of the growth, and sleep at night.