Blackjack doubling down: when to double. When to hold back.

Doubling down means adding a second bet, usually equal to your first, in exchange for exactly one more card. Your turn then ends, even if the card is a bad one.

The quick rule: double hard 9 against 3 to 6, 10 against 2 to 9 and 11 against 2 to 10. Against an ace, and on soft hands, the chart has the answer.

Check my hand See a $10 example

One extra bet. One card. A decision made on the hand in front of you.

When to double down

What does the dealer do on soft 17?

6 decks · dealer checks for blackjack · double on any first two cards

Dealer’s upcard →
You hold	2	3	4	5	6	7	8	9	10	A
Hard 9	–	D	D	D	D	–	–	–	–	–
Hard 10	D	D	D	D	D	D	D	D	–	–
Hard 11	D	D	D	D	D	D	D	D	D	–
A,2	–	–	–	D	D	–	–	–	–	–
A,3	–	–	–	D	D	–	–	–	–	–
A,4	–	–	D	D	D	–	–	–	–	–
A,5	–	–	D	D	D	–	–	–	–	–
A,6	–	D	D	D	D	–	–	–	–	–
A,7	–	Ds	Ds	Ds	Ds	–	–	–	–	–
A,8	–	–	–	–	–	–	–	–	–	–

D double, otherwise hit. Ds double, otherwise stand. – do not double.
A is an ace; 10 includes J, Q and K. Soft 17 is A,6. Two fives count as hard 10.

Check the rules that change the answer

Page changelog

Sep 17, 2026 Rebuilt around the question. The doubling chart with an S17/H17 switch opens the page, followed by a hand checker solved for your exact cards, the $10 payout example, the mechanics, three worked hands with every double in one table, the maths with an EV comparison, the rules, five mistakes, six practice hands and the questions people ask. The closing summary was rewritten in the page’s own terms.

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Sep 16, 2026 The when-to-double grid now opens the page. The ranked table of every doubling cell became a table by hand type (the full list folds away underneath), and every section was cut to the facts that carry it.

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Your cards, your answer

Should you double this hand?

Choose your first two cards and the dealer’s face-up card. The answer uses the dealer rule set in the chart above.

Your first card Your second card Dealer shows

Dealer stands on soft 17 (S17)

Six decks · dealer checks for blackjack · double on any first two cards · double after split · no surrender.

6 + 5 (hard 11) vs 6 · S17

Double down

Doubling returns +$6.81 per $10 bet on average; hitting returns +$3.41. Exactly twice as much: you were never drawing twice here, so the second draw you give up is worth nothing.

If doubling is unavailable, hit.

Try a common question:

When does this answer apply?

It is basic strategy for your first two cards, solved for those exact cards in the game described above. Against a 10 or an ace the dealer has already checked and does not have blackjack. Split answers assume doubling after a split is allowed. It is not a card-counting tool. If you have already hit, are playing split aces, or your table’s rules differ, read the rules that change the answer.

What happens to your money

A $10 bet. Three possible outcomes.

$10Original bet

$10Added bet

$20at stake

Put another $10 beside your original $10. You receive one card, and both bets are settled on the same hand.

An ordinary win still pays even money. You have doubled the stake, not changed the payout to 2 to 1.

You win

+$20net profit
$40 comes back, including your $20 stake.

You lose

−$20net loss
Both the original and the added bet are gone.

You push

$0profit or loss
Your full $20 stake is returned.

Drawing a 10 onto 11 makes a three-card 21. It is not a natural blackjack and does not get the 3-to-2 payout.

The mechanics

How to double down, step by step.

Make the decision before taking another card. Once you double, the hand gets exactly one more.

Check your first two cards.
Compare your hand with the dealer’s upcard. Confirm the table lets you double on that total; some allow only 9 to 11, or 10 and 11.
Add the extra wager.
At a table: say “double” and place an equal bet beside your original one, not on top of it. Online: press Double while the option is offered.
Take one card. Then stand.
You cannot hit again, whatever the card. The dealer plays out their hand, and both bets win, lose or push together.

Know your hand

Hard hands. Soft hands. Real decisions.

A hard hand has no ace counting as 11: 6 + 5 is hard 11. A soft hand does: A + 7 is soft 18. The ace can drop to 1, so one card cannot bust a two-card soft hand.

The classic double

65 vs 6

Hard 11 against 6

Double under both rules.

You are already the favourite and the dealer’s six busts more than four times in ten. Doubling returns +$6.81 per $10 bet on average against +$3.41 for hitting.

If doubling is unavailable: hit.

The pair that stays together

55 vs 9

Two fives against 9

Double. Keep your 10.

Splitting turns a useful ten into two hands that start from five. As a hard 10 it is a double: +$1.50 per $10 against +$1.18 for hitting and −$5.33 for splitting.

If doubling is unavailable: hit.

The rules make the difference

A7 vs 2

Soft 18 against 2

S17: stand. H17: double.

Standing returns +$1.24 and doubling +$1.21 when the dealer stands on soft 17; when the dealer hits it, doubling edges ahead. Same cards, different table.

If doubling is unavailable: stand.

Every double in one table

Six decks · dealer checks for blackjack · double on any first two cards · double after split · no surrender. These are the doubling cells, not the whole chart: check pairs for splitting first.

Dealer upcards to double against
Your hand	S17Dealer stands on soft 17	H17Dealer hits soft 17	If you cannot double
Hard 9	3–6	3–6	Hit
Hard 10	2–9	2–9	Hit
Hard 11	2–10	2–A	Hit
5,5 (play as hard 10)	2–9	2–9	Hit
A,2 / A,3	5–6	5–6	Hit
A,4 / A,5	4–6	4–6	Hit
A,6	3–6	3–6	Hit
A,7	3–6	2–6	Stand
A,8	None	6	Stand

“If you cannot double” applies only in the listed cells. A is an ace; 10 includes J, Q and K.

A clean one-page reference with both dealer rules.

Blackjack doubling down

Add one bet. Take one card. Then stand.

Six decks · dealer checks for blackjack · double on any first two cards · double after split · no surrender. Check pairs for splitting first; 5,5 is a hard 10.

Dealer upcards to double against
Your hand	S17Dealer stands on soft 17	H17Dealer hits soft 17	If you cannot double
Hard 9	3–6	3–6	Hit
Hard 10	2–9	2–9	Hit
Hard 11	2–10	2–A	Hit
5,5 (play as hard 10)	2–9	2–9	Hit
A,2 / A,3	5–6	5–6	Hit
A,4 / A,5	4–6	4–6	Hit
A,6	3–6	3–6	Hit
A,7	3–6	2–6	Stand
A,8	None	6	Stand

Cannot double? Use the fallback only in the listed cells. S17: dealer stands on soft 17. H17: dealer hits soft 17. A is an ace; 10 includes J, Q and K.

What the extra bet means

$10 original + $10 added = $20 at stake. Win: $20 profit ($40 back). Lose: $20 gone. Push: $20 returned. A three-card 21 is not a natural blackjack.

Beat The Fish · beatthefish.com/blackjack/strategy/doubling-down/ · solved by our blackjack engine for the game above; other rules can change the play.

The reason behind the move

Why the bigger bet can be the better play.

Doubling has a price: you give up the right to keep drawing. In the right spot, a second bet is worth more than those future hits.

With 6 + 5 against a dealer 6 you would stand after your next card anyway, so the draw you give up is worth nothing. Doubling lets a second bet earn alongside the first without changing how you play the hand.

Against an ace at an S17 table the balance flips. You may need to hit again after a small card, and keeping that option is worth more than the extra bet.

Expected value is an average, not a promise. A correct double can lose twice your original bet. It improves the expected return of this decision; it does not guarantee a winning hand or session.

Across the whole game the option is worth about 1.5% of every bet: the same six-deck game costs 1.95% with doubling forbidden and 0.46% with it allowed. The house edge calculator prices it against every other rule.

Compare a starting hand

Average net result per $10 original bet. Six decks, dealer stands on soft 17, these exact cards.

Hit+$3.41

Double+$6.81

Double: about $3.40 more expected profit per $10 bet in this spot.

Solved by our engine from the exact three cards with a full six-deck shoe, dealer blackjack ruled out. Averages over repeated identical situations, not a single-hand result.

What about doubling for less?

Most tables let you add less than your original bet, but you still give up all further hits. On 11 against a 6, a half double returns +$5.11 per $10 against +$6.81 for the full double and +$3.41 for hitting: better than hitting, worse than doing it properly. If the full second bet feels too big, the fix is a smaller first bet.

Read the table

Same cards. Different rules. Different answer.

Check these on the table sign or in the game’s rules before using the chart.

Dealer hits or stands on soft 17: Soft 17 includes A + 6, the ace still counting as 11. H17 adds three doubles to the S17 chart: hard 11 against an ace, A,7 against a 2 and A,8 against a 6.
Which totals may double: “Any two cards” includes soft hands. A game limited to 9 to 11 removes the soft doubles and costs about 0.10% of every bet; 10 and 11 only also removes hard 9 and costs about 0.19%. Use the fallback play in those cells. The house edge calculator prices any rule set.
Doubling after splitting: DAS means a two-card hand made by a split can double. Split aces usually get one card each and cannot; check that rule separately. Pair splitting prices the difference.
When the dealer checks for blackjack: The chart assumes the dealer checks for blackjack before you act, so a doubled bet is never lost to a dealer natural. In a no-hole-card game where a dealer blackjack takes all bets, a double against a 10 or an ace risks the extra bet too; the chart is not solved for that game.
Deck count and variants: Fewer decks move a handful of cells; single deck adds hard 9 against a 2, for instance. Spanish 21 and other variants need their own chart. The chart page solves the whole chart for one to eight decks.

Avoid the easy errors

Five mistakes that cost the extra bet.

“Always double 11.” Against an ace at an S17 table, hitting is right; doubling costs about 2% of a bet.
Ignoring the soft doubles. A,6 against a 5 doubles for +$2.00 per $10 against +$1.00 for hitting.
Splitting fives. Two fives are a hard 10. Against a 6, doubling returns +$5.98 per $10; splitting +$0.93.
Expecting another card. A double ends your drawing after one card, whatever it is.
Doubling to recover losses. Earlier hands do not change this one. Hard 12 against a 6 is a stand; doubling it costs about 19% of a bet.

Remember the trade-off. You are putting more money on the table and giving up further hits. Decide from the current hand and the actual table rules.

Try it before you play

Six hands. Make the call.

The decisions people hesitate over. Each hand shows its dealer rule, and every answer comes with the numbers.

No money involved. Six decks, dealer checks for blackjack, double after split, no surrender. Want more than six? The basic strategy trainer deals hands for as long as you like and keeps the ones you get wrong.

Hand 1 of 6Dealer stands on soft 17

Your hand

Dealer

What would you do?

The last details

Your doubling questions, answered.

Can you double down after hitting?

Usually not. Standard blackjack limits doubling to your first two cards; a variant has to allow later doubles explicitly.

Can you double down after splitting?

Yes, where the table allows it (DAS) and the new hand qualifies. Split aces usually get one card each and cannot.

Should you double 11 against an ace?

In the six-deck game where the dealer checks for blackjack: hit under S17, double under H17. At an S17 table hitting returns +$1.47 per $10 and doubling +$1.25.

Should you double soft 18?

A,7 doubles against 3 to 6 under S17 and 2 to 6 under H17. Where doubling is not allowed in those cells, stand.

Can you double for less than your original bet?

Most tables allow it, and you still get only one card. On 11 against a 6 a half double returns +$5.11 per $10 against +$6.81 for the full one.

Does doubling down pay 2 to 1?

No. An ordinary win pays even money on the combined stake: $10 doubled to $20 wins $20, with $40 coming back including your stake.

What if the double-down card makes 21?

That is a three-card 21, not a natural blackjack. It wins even money, and a dealer 21 pushes it.

Can you hit again, or double a second time?

Not in ordinary blackjack. The double commits you to one card and then a stand, whatever total you reach.

Is doubling down the same as the Martingale?

No. Doubling down adds to the current hand because the hand is worth it. The Martingale raises later bets after losses and does nothing to the odds.

Why is the Double button greyed out?

You have already hit, the total does not qualify at this table, you are on a restricted split hand, or your balance will not cover the extra bet. Play the hand’s normal hit-or-stand decision.

Can you double on any total?

Some tables allow a double on any first two cards, which does not make every double a good one: hard 12 against a 6 is a stand, and doubling it costs about 19% of a bet. Permission and reason are different things.

Before the next hand

Double the hand, not the feeling.

The second bet is the point. Three things decide whether to place it.

Hard 9, 10 and 11 carry the value

Double 11 against 2 to 10, 10 against 2 to 9, 9 against 3 to 6. Get those right every time before anything else.

Soft doubles are about the dealer’s card

A,2 to A,7 double against a 5 or 6, and more of them against a 3 or 4. The ace means the card cannot bust you; the dealer’s weak card does the rest.

Check the felt, then commit

A dealer who hits soft 17 adds 11 against an ace, soft 18 against a 2 and soft 19 against a 6. Whatever the rule, one card means one: you take the result, including losing both bets.