Blackjack Side Bet Odds Calculator
Calculate the odds, house edge, and expected value for popular blackjack side bets including 21+3, Perfect Pairs, Insurance, Lucky Ladies, and more.
Formula:House Edge = (1 - Total Return) × 100
House Edge
22.32%
Expected Value
$-1.12
Per bet
Recommendation
Very high house edge - avoid this bet
Select the side bet to analyze
$
Amount wagered on the side bet
Affects Perfect Pairs and some other bets
Payout Table - 21+3
| Outcome | Probability | Payout | Contribution |
|---|---|---|---|
| Suited Three of a Kind | 0.0455% | 100:1 | 4.55% |
| Straight Flush | 0.2170% | 40:1 | 8.68% |
| Three of a Kind | 0.2350% | 30:1 | 7.05% |
| Straight | 3.2600% | 10:1 | 32.60% |
| Flush | 4.9600% | 5:1 | 24.80% |
| Total Return | 77.68% | ||
Quick Answer
The 21+3 side bet has a house edge of 22.32%. This is a high house edge bet that should be avoided for serious play.
Key Facts
- •Side bets typically have 2-25% house edge vs 0.5% for basic blackjack
- •Insurance is only profitable at true count +3 or higher when counting
- •21+3 combines your cards with dealer upcard for poker hands
- •Perfect Pairs odds improve with more decks in play
- •Side bets are designed for entertainment, not profit
Frequently Asked Questions
What are the best blackjack side bets?
The best side bets are those with the lowest house edge. 21+3 typically has around 3-7% house edge depending on paytable, while Perfect Pairs can range from 2-11%. Insurance is almost always a bad bet at 7.69% house edge unless you're counting cards.
Should I take insurance in blackjack?
Generally no. Insurance has a 7.69% house edge with a standard deck. However, card counters may take insurance when the true count indicates more tens remain in the deck (roughly +3 or higher true count).
What is the house edge on 21+3?
The 21+3 side bet typically has a house edge between 3-7% depending on the specific paytable used. The bet wins when your two cards plus the dealer's upcard form a poker hand (flush, straight, three of a kind, etc.).
Are Perfect Pairs worth playing?
Perfect Pairs has a house edge of 2-11% depending on deck count and paytable. With standard 6-deck rules and 25:1 for perfect pairs, the edge is around 4-6%. It's one of the lower-edge side bets available.
Try These Examples
Quick-start with common scenarios
How this works
Calculations follow the published mathematics of the game — combinatorics for cards, probability theory for dice, and expected-value accounting for wagers. Results are verified against independent references (primarily Wizard of Odds). No calculation here is an opinion or recommendation; it is arithmetic applied to the rules of the game.
What this tool can’t do
When to consult a professional
This tool computes probability and expected value. It is not a betting system and cannot predict the outcome of any individual wager. If gambling is causing problems for you or someone you know, call the National Problem Gambling Helpline at 1-800-GAMBLER.
Sources
- [1]Wizard of Odds — Michael Shackleford, ASAIndustrywizardofodds.comAccessed Apr 21, 2026
Actuary; widely cited casino-game probability reference. Used for house-edge and EV verification.
- [2]National Council on Problem GamblingOfficial sourcencpgambling.orgAccessed Apr 21, 2026
Responsible-gambling guidance and 1-800-GAMBLER helpline.
Joseph OrdunaFounder & Software Engineer
Full-stack software engineer specializing in embedded systems, web architecture, and AI/ML. Founder of Practical Web Tools. Built the gesture-controlled drone IP acquired by KD Interactive (Aura Drone, sold on Amazon).
House Edge
22.32%
Expected Value
$-1.12
Per bet
Recommendation
Very high house edge - avoid this bet