Blackjack Double Down Calculator: Maximize Your Winning Hands

Doubling down means doubling your bet to receive exactly one more card. Our calculator shows every profitable doubling situation, turning your edge hands into maximum profit opportunities.

What Is Doubling Down?

Doubling down lets you double your original bet in exchange for receiving exactly one additional card (no more hits). It's most valuable with totals of 10 or 11, where you're likely to make a strong hand against a weak dealer.

Quick Answer: Always double 11 vs dealer 2-10. Always double 10 vs dealer 2-9. Double 9 vs dealer 3-6. Double soft 13-17 vs dealer 5-6, soft 15-17 vs dealer 4, soft 17 vs dealer 3. Never double hard 12+ (hit or stand instead). Doubling correctly can reduce house edge by ~0.2% compared to just hitting.

How to Use Our Calculator

Use the Blackjack Double Down Calculator →

Enter your hand and dealer upcard to see if doubling is optimal.

Step-by-Step Instructions

1. Enter Your Hand: Total or cards

2. Input Dealer Upcard: Showing card

3. View Recommendation: Double, hit, or stand

4. See EV Comparison: Expected value of each action

5. Check Rule Variations: DAS, double any, etc.

Input Fields Explained

Field	Description	Example
Your Hand	Cards or total	6-5 (11)
Dealer Upcard	Showing card	6
Recommendation	Optimal action	DOUBLE
EV if Double	Expected value	+0.67
EV if Hit	Expected value	+0.39
Advantage	Double vs hit	+0.28 units

Hard Total Double Strategy

Hard 11

Dealer Shows	Action
2-10	DOUBLE
Ace	Hit (or double in some rules)

Why 11 is best for doubling:

Hard 11 + one card:
P(making 17-21) = 58%
P(making 21) = 31%

Against weak dealer:
Massive positive expectation

Hard 10

Dealer Shows	Action
2-9	DOUBLE
10	Hit
Ace	Hit

Analysis:

Hard 10 + one card:
P(making 17-21) = 54%
P(making 20-21) = 39%

Doubling 10 vs 10:
Marginal—dealer ties too often

Hard 9

Dealer Shows	Action
3-6	DOUBLE
2, 7-A	Hit

Why limited range:

Hard 9 + one card:
P(making 17-21) = 50%

Only profitable vs weakest dealers

Hard 8 and Below

Hand	Action
Hard 8	Hit (rarely double)
Hard 7 or less	Hit always

Never double hard 8 in standard games

Hard 12 and Above

Hand	Action
Hard 12-16	Hit or Stand (never double)
Hard 17-21	Stand always

Never double stiff hands—one card may bust

Soft Hand Double Strategy

Soft 13-14 (A-2, A-3)

Dealer Shows	Action
5-6	DOUBLE
2-4, 7-A	Hit

Soft 15-16 (A-4, A-5)

Dealer Shows	Action
4-6	DOUBLE
2-3, 7-A	Hit

Soft 17 (A-6)

Dealer Shows	Action
3-6	DOUBLE
2, 7-A	Hit

Soft 18 (A-7)

Dealer Shows	Action
3-6	DOUBLE
2, 7-8	Stand
9-A	Hit

Soft 19-20 (A-8, A-9)

Dealer Shows	Action
All	Stand

Never double soft 19+

Expected Value Analysis

EV by Hand (vs Dealer 6)

Your Hand	EV Double	EV Hit	EV Stand	Best
11	+0.67	+0.39	-0.12	Double
10	+0.56	+0.29	-0.21	Double
9	+0.25	+0.17	-0.15	Double
A-6	+0.30	+0.09	-0.00	Double
A-7	+0.26	+0.07	+0.12	Double
A-2	+0.12	+0.06	-0.14	Double

EV by Hand (vs Dealer 10)

Your Hand	EV Double	EV Hit	EV Stand	Best
11	+0.18	+0.12	-0.54	Double
10	-0.04	+0.04	-0.54	Hit
9	-0.18	-0.04	-0.54	Hit

Real-World Examples

Example 1: Classic Double

Your hand: 7-4 (hard 11) Dealer shows: 6 Bet: $25

Analysis:

• 11 vs 6 is prime doubling territory
• EV(double) = +0.67 per unit
• EV(hit) = +0.39 per unit

Action: DOUBLE to $50

Expected profit: $25 × 0.67 = $16.75

Example 2: Soft Double

Your hand: A-6 (soft 17) Dealer shows: 5 Bet: $50

Analysis:

• Soft 17 vs 5 is double situation
• Can't bust (ace counts as 1 if needed)
• Dealer likely to bust

Action: DOUBLE to $100

Example 3: When Not to Double

Your hand: 6-4 (hard 10) Dealer shows: Ace Bet: $30

Analysis:

• 10 vs Ace is NOT a double
• Dealer too strong
• EV(double) < EV(hit)

Action: HIT (don't double)

Example 4: Split-Then-Double

Your hand: 5-5 (after splitting) Dealer shows: 6 Bet: $20 (after split)

Analysis:

• Split 5s? No, never split 5s
• If you somehow have 10 from a split
• Still double if DAS allowed

Action: DOUBLE to $40

Rule Variations

Double After Split (DAS)

Rule	Impact
DAS allowed	Favorable, changes split decisions
DAS not allowed	Less favorable for player

House edge difference: ~0.14%

Double Any Two Cards

Rule	Impact
Any two cards	Standard, best for player
9-11 only	Restricted, worse
10-11 only	Very restricted, worst

House edge impact:

Double any: Baseline
9-11 only: +0.09% edge
10-11 only: +0.18% edge

Dealer Hits Soft 17

Dealer hits S17: Marginal change to doubles
Dealer stands S17: Standard

More doubles slightly beneficial with H17

Common Doubling Mistakes

1. Not Doubling Soft Hands

Mistake: Hit A-6 vs 5 Problem: Missing profitable double opportunity Fix: Learn soft doubling spots (vs 3-6)

2. Doubling 12 or Higher

Mistake: Double 12 vs 6 Problem: Can bust, lose double bet Fix: Never double hard 12+

3. Doubling 10 vs 10

Mistake: "10 vs 10, I should double" Problem: EV(hit) > EV(double) vs 10 Fix: Only double 10 vs 2-9

4. Afraid to Double 11 vs Ace

Mistake: Hit 11 vs Ace Problem: Depends on rules (H17 vs S17) Fix: Double in H17 games, hit in S17 usually

Counting and Doubling

True Count Adjustments

Standard Play	Counting Play
Double 11 vs A: Hit	Double at TC +1 (H17)
Double 10 vs A: Hit	Double at TC +4
Double 10 vs 10: Hit	Double at TC +4
Double 9 vs 2: Hit	Double at TC +1
Double 9 vs 7: Hit	Double at TC +3
Double 8 vs 5: Hit	Double at TC +5
Double 8 vs 6: Hit	Double at TC +2

Why Count Affects Doubles

High count = more 10s remaining
More 10s = better for doubling
Drawing 10 to 11 = 21

Also: Dealer more likely to bust

Mathematical Foundation

Double Down Math

EV(double) = 2 × EV(one card and stop)
EV(hit) = EV(optimal play after one card)

Double when:
EV(double) > EV(hit)
2 × EV(one card) > EV(optimal continuation)

Probability Breakdown (11 vs 6)

P(drawing 10 to 21) = 30.8%
P(drawing 9 to 20) = 7.7%
P(drawing 8 to 19) = 7.7%
...
P(dealer busts) = 42%

Combined: Strong positive expectation

Frequently Asked Questions

Should I double 11 vs every dealer card?

Double 11 vs 2-10 always. Against Ace, it depends on rules (H17/S17) and sometimes count.

Is doubling soft hands important?

Yes. Soft doubles add ~0.14% to your expected return. They're often overlooked but valuable.

Can I double after splitting?

Depends on casino rules (DAS = Double After Split). When allowed, it's valuable and affects split decisions.

What if I can only double 10-11?

Restricted rules cost ~0.18% in house edge. You lose soft doubling and 9 vs weak dealers.

Should I double in tournaments?

Sometimes deviate based on chip situation. Double more aggressively when behind, less when ahead.

Does doubling always mean more money at risk?

Yes. That's the tradeoff—higher variance, but positive EV in correct situations.

Pro Tips

• Memorize hard doubles: 11 vs 2-10, 10 vs 2-9, 9 vs 3-6

• Learn soft doubles: Biggest leak for most players

• Check house rules: DAS and double restrictions matter

• Don't be timid: Doubling is expected, not aggressive

• Count adjustments: Add doubles in positive counts

Related Calculators

• Blackjack Basic Strategy Calculator - Complete strategy
• Blackjack House Edge Calculator - Rule impact
• Blackjack Expected Value Calculator - Hand EV
• Blackjack Card Counting Calculator - Count strategy
• Blackjack Surrender Calculator - Surrender decisions

Conclusion

Doubling down transforms favorable situations into maximum profit opportunities. Our calculator shows every correct double—hard 11 against almost everything, hard 10 against weak dealers, hard 9 against weakest dealers, and often-forgotten soft hand doubles. Master these decisions and extract full value from your winning positions.

Calculate Double Down Strategy Now →

Doubling isn't gambling—it's math. Our calculator proves exactly when doubling has positive expected value versus hitting, showing the advantage you gain by putting more money in play with favorable hands. Learn the spots, double with confidence, and watch your expected return improve.