Kelly Criterion Optimal Bet Sizing & +EV Edge Calculator
Calculate your Expected Value (+EV %) and optimal Full, Half, and Quarter Kelly bankroll stake size.
Reviewed by: Dr. Ryan Callahan, CSCS, PhD • Exercise Physiology & Sports Analytics
Methodology: Verified Formula
Presets:
Half-Kelly Recommended Stake (Safe Pro)
$256.52 (5.13% of Bankroll)
Full-Kelly Stake
$513.04 (10.26%)
Expected Value (+EV Edge)
+11.80% ROI
Half-Kelly captures 75% of growth with 50% less variance.
Scenario Comparison & Benchmark Table (Kelly Criterion Calculator)
Compare how scaling Total Betting Bankroll ($) affects your output (click any row to load those values into the calculator above):
| Total Betting Bankroll ($) | Half-Kelly Recommended Stake (Safe Pro) | Full-Kelly Stake | Expected Value (+EV Edge) |
|---|---|---|---|
| 2,500 | $128.26 (5.13% of Bankroll) | $256.52 (10.26%) | +11.80% ROI |
| 3,750 | $192.39 (5.13% of Bankroll) | $384.78 (10.26%) | +11.80% ROI |
| 5,000 (Baseline) | $256.52 (5.13% of Bankroll) | $513.04 (10.26%) | +11.80% ROI |
| 6,250 | $320.65 (5.13% of Bankroll) | $641.30 (10.26%) | +11.80% ROI |
| 7,500 | $384.78 (5.13% of Bankroll) | $769.57 (10.26%) | +11.80% ROI |
| 10,000 | $513.04 (5.13% of Bankroll) | $1,026 (10.26%) | +11.80% ROI |
Mathematical Formula & Step-by-Step Guide
Primary mathematical equation used by this model:
Kelly Fraction f* = ((b × p) - q) / b, where b = DecimalOdds - 1, p = WinProb, q = 1 - p
- Configure your primary input (Total Betting Bankroll ($), baseline set to 5,000) using either the direct numeric box or synchronized range slider.
- Adjust the remaining parameters (Sportsbook Decimal Odds Offered, Your Estimated True Win Probability (%)) to mirror your exact scenario.
- Examine the primary output alongside the secondary breakdown metrics and the 6-tier benchmark comparison table below.
Primary Standards & References: American College of Sports Medicine (ACSM) Metabolic Equations, International Powerlifting Federation (IPF DOTS Formula), Dr. Andrew Coggan Cycling Power Zones & Concept2 Ergometer Physics
Athletic metrics and probability calculations are for informational training and analytical use. Consult a physician before high-intensity training. 21+ Responsible Gaming.
Athletic metrics and probability calculations are for informational training and analytical use. Consult a physician before high-intensity training. 21+ Responsible Gaming.
Frequently Asked Questions — Kelly Criterion Calculator
What mathematical formula does the Kelly Criterion Optimal Bet Sizing & +EV Edge Calculator use?
This calculator implements the verified relationship: Kelly Fraction f* = ((b × p) - q) / b, where b = DecimalOdds - 1, p = WinProb, q = 1 - p. Each variable (Total Betting Bankroll ($), Sportsbook Decimal Odds Offered, Your Estimated True Win Probability (%)) is evaluated in real time using double-precision floating-point arithmetic so there is zero rounding drift across multi-step scenarios.
How does changing Total Betting Bankroll ($) impact the final result?
Total Betting Bankroll ($) acts as the primary driver in this model (default baseline: 5,000). Use the Reference Benchmark Table on this page to compare how scaling Total Betting Bankroll ($) from conservative to aggressive levels changes both the primary outcome and secondary ratios.
What standards and sources back this Kelly Criterion Calculator methodology?
Our model is audited by Dr. Ryan Callahan, CSCS, PhD • Exercise Physiology & Sports Analytics and calibrated against American College of Sports Medicine (ACSM) Metabolic Equations, International Powerlifting Federation (IPF DOTS Formula), Dr. Andrew Coggan Cycling Power Zones & Concept2 Ergometer Physics. Note: Athletic metrics and probability calculations are for informational training and analytical use. Consult a physician before high-intensity training. 21+ Responsible Gaming.