An Exacta is one of the simplest vertical exotic wagers in horse racing: you select the first two finishers in exact order. Payouts come from a pari-mutuel pool, so even a small ticket can produce a large return when the winning combination is lightly bet by the public.
The challenge? Predicting the exact order gets expensive fast once you start boxing multiple horses. Use the free calculator below to price a straight, box, key or part-wheel ticket, then scale a displayed payoff to your stake on the Payout tab.
n × (n−1) × stake. See the full chart below.Exacta Calculator
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What Is an Exacta?
An exacta is a pari-mutuel wager on the exact 1st-2nd finishing order of a race. A straight ticket names one exact order and costs a single unit stake. Every other construction — box, key wheel, key box, part wheel — is simply a bundle of straight combinations bought on one ticket, so the price is always the number of combinations multiplied by your unit stake. A two-horse box is sometimes called a reverse exacta (or reverse forecast in UK markets): two combinations, twice the unit stake.
Exacta Ticket Cost Formulas
Total cost = Valid combinations × Unit stake
Each construction generates a different combination count:
| Construction | Combinations | Example |
|---|---|---|
| Straight | 1 | One exact order = 1 × stake |
| Box (n horses) | n × (n−1) | 4 horses = 12 |
| Key Wheel (banker + m others) | m | Over 4 others = 4 |
| Key Box (banker + m others) | 2 × m | With 4 others = 8 |
| Part Wheel | Count of valid pairs | Depends on your legs |
Exacta Box Cost Chart: 2 to 10 Horses
When you “box” horses, they can finish 1st or 2nd in any order. This removes the need to predict which horse wins — but each additional horse multiplies (not just adds to) the combination count. The step-by-step logic for 4 horses: 4 can finish 1st, 3 remain for 2nd — 4 × 3 = 12 combinations.
| # Horses | Combinations | $1 Cost | $2 Cost | $5 Cost |
|---|---|---|---|---|
| 2 | 2 | $2 | $4 | $10 |
| 3 | 6 | $6 | $12 | $30 |
| 4 | 12 | $12 | $24 | $60 |
| 5 | 20 | $20 | $40 | $100 |
| 6 | 30 | $30 | $60 | $150 |
| 7 | 42 | $42 | $84 | $210 |
| 8 | 56 | $56 | $112 | $280 |
| 9 | 72 | $72 | $144 | $360 |
| 10 | 90 | $90 | $180 | $450 |
Straight, Box, Key Wheel and Key Box
Straight Bet
The simplest ticket: one horse to win, one to finish second, in that exact order.
#5 over #2 → 1 combination = $2.00 at $2
If they finish 2-5 instead of 5-2, the ticket loses — no flexibility, minimum cost.
Box Bet
Pick a group of horses; any two of them finishing 1st-2nd in either order wins.
Box #1, #4, #7 → 1-4, 1-7, 4-1, 4-7, 7-1, 7-4 → 6 combinations = $12.00 at $2
Key Wheel
Lock one horse (the banker) into a specific position — 1st, or 2nd for a “key underneath” — and let the others fill the remaining spot. The combination count is simply m, the number of other horses, and the cost is identical whichever position you choose.
Key: #3 over #2, #5, #9 → 3-2, 3-5, 3-9 → 3 combinations = $3.00 at $1
Compare: boxing all 4 of those horses costs $12 at $1. Keying saves $9 — the price of dropping every combination where #3 misses 1st.
Key Box
The looser variant: the banker only has to finish in the top two, in either position, which doubles the count to 2 × m.
Key box: #3 with #2, #5, #9 → 3-2, 3-5, 3-9, 2-3, 5-3, 9-3 → 6 combinations = $6.00 at $1
How to Read Exacta Ticket Notation
Tickets and past-performance notes use a compact “over” notation. “8 over 4, 5, 6” means #8 must win, with #4, #5 or #6 finishing second — three combinations: 8-4, 8-5 and 8-6. The reverse, “4, 5, 6 over 8”, keys #8 underneath: 4-8, 5-8 and 6-8, also three combinations. A box is written as “1-4-7 box” — every order among the listed runners. The calculator’s Part Wheel tab prints your selections in this notation automatically.
Part Wheel: Calculator and Examples
The part wheel gives you full control over which horses appear in which position — a flexible construction for bettors whose confidence differs by finishing position, because it lets you invest more heavily in the outcomes you consider most likely. Use the Part Wheel tab in the calculator above: pick horse numbers for each position and it prices the ticket by counting valid pairs, exactly the way the tote terminal does.
Example 1: Separate Groups
1st: #2, #5 | 2nd: #3, #7, #8
The groups share no horses, so every pairing is valid: 2-3, 2-7, 2-8, 5-3, 5-7, 5-8 — 6 combinations, $6.00 at $1.
Example 2: Overlapping Groups
1st: #2, #5 | 2nd: #3, #5, #7, #8
Naive multiplication says 2 × 4 = 8, but the pairing 5-5 is impossible — a horse cannot finish 1st and 2nd. The valid pairs are 2-3, 2-5, 2-7, 2-8, 5-3, 5-7, 5-8: 7 combinations, $7.00 at $1.
How Exacta Payouts Work
Payouts are pari-mutuel: every bet of this type goes into one pool, the track removes its takeout, which varies by jurisdiction and track, and the remaining pool is divided among the winning units. In simplified form, the payoff per base unit is:
Payoff per base unit = Net pool ÷ Winning units on the combination
Exact calculations follow the rules of the specific pool and track. Nobody can know the final dividend before wagering closes, because the pool and the money on each order keep moving until post time. What you can do is read the probable payoffs and scale them to your stake.
How to Scale a Probable Payoff
Probable and final payoffs are always quoted against a base amount — often $1, sometimes $2 — and official results print that base next to the number. Check it, then scale only if your unit stake differs:
Your return = Displayed payoff × Your unit stake ÷ Displayed base
Example: the board shows a payoff of $45.50 at a $1 base, and your unit stake on the winning order is $5. Your return is 45.50 × 5 ÷ 1 = $227.50. If that order sat on a 12-combination box that cost $60 at $5, your net profit is $227.50 − $60 = $167.50 — the return scales from the unit stake of the one winning combination, never from the full ticket cost. The Payout tab in the calculator runs this arithmetic for any base, including custom ones.
Why Win Odds Cannot Predict an Exacta Dividend
A common question: two horses go off at 4-1 and 6-1 — what does the exacta pay? There is no formula for it. You cannot multiply the win odds of two horses to get the dividend, because the wager has its own separate pool: the payoff depends on how much money sits on that exact 1st-2nd order, not on the win-pool odds of the individual runners. Two races with identical win odds can produce very different dividends. The only real preview is the probable payoffs display for this pool, read a few minutes before post time.
Exacta Box vs Quinella Box
Both cover the top two finishers in either order — the difference is how combinations are counted and priced, and both can be boxed with three or more horses.
| Feature | Exacta Box | Quinella Box |
|---|---|---|
| What it covers | Top two, either order | Top two, either order |
| Combinations | n × (n−1) | n × (n−1) ÷ 2 |
| 3 horses | 6 | 3 |
| 4 horses | 12 | 6 |
| 5 horses | 20 | 10 |
| Pool | Own pari-mutuel pool | Separate pool, where offered |
At the same unit stake, the ordered wager always contains exactly twice as many combinations, because each finishing order is bought separately, while a quinella pays either order from a single combination. Which one returns more in a given race depends only on how the public has loaded each pool — there is no universal rule.
Minimum Stakes and Track Differences
Many U.S. programs use a $1 base for this wager, while some require $2 for a straight ticket or set different minimums for boxes and wheels. The minimum varies by track, race and wagering platform — check the wager menu before pricing your ticket, and use the Custom stake field in the calculator for anything non-standard, from $0.10 up to high-roller units. Licensed ADW platforms normally support straight, box, key and part-wheel tickets, although available constructions and minimums vary.
Scratches and Refunds
At many tracks, combinations containing a scratched horse are refunded. Example at $1: a 3-horse box is 6 combinations ($6); if one horse scratches, the 4 that included it are refunded ($4), leaving a 2-horse box ($2). Treatment can vary by jurisdiction and by the timing of the scratch — check the official track rules for the card you are playing.
Box vs Key vs Part Wheel: When to Use Each
Use a BOX when:
- You like 3–4 horses but cannot separate them
- You have no strong opinion on who wins vs. who places
- The field is short (fewer than 8 runners)
Use a KEY when:
- One horse stands out — wheel it if you know the position, or use the looser variant if you only trust top 2
- Consider keying underneath if a horse keeps running second
- You want wide coverage at a fraction of the cost
Use a PART WHEEL when:
- Your confidence differs by position (2 contenders to win, 4–5 for second)
- The field is large and a full box is too expensive
- You want maximum control over the ticket structure
A box provides wider coverage but costs more; a key construction costs less but loses whenever the banker misses its assigned condition. Choose by how well you can rank your contenders, not by which ticket feels safer.
Related Horse Racing Calculators
- Horse Racing Betting Calculators — Full hub of racing tools
- Trifecta Calculator — Pick the top 3 finishers
- Superfecta Calculator — Pick the top 4 with a $0.10 minimum
- Pool Bet Payout Calculator — Pick 4 / Pick 6 payout estimation
- Kelly Criterion Calculator — Optimal bet sizing
- Exotic Bets Explained — Complete guide to all wager types
Frequently Asked Questions (FAQ)
How much does a $1 exacta box cost for 3, 4, and 5 horses?
n × (n−1). Availability of the $1 base varies by track and platform.How much does a $2 exacta box cost for 4, 5, and 6 horses?
What is the difference between a key wheel and a key box?
m combinations, and the cost is the same whichever position you key. A key box lets the banker finish 1st or 2nd, which doubles the count to 2 × m. Banker over 4 others: wheel = 4 combinations ($4 at $1), key box = 8 ($8 at $1).What does “8 over 4, 5, 6” mean?
Can I calculate my exacta payout from the horses’ win odds?
How is the exacta payout calculated?
your return = displayed payoff × your unit stake ÷ displayed base.Can this calculator estimate my exacta payout?
What is the minimum stake?
What’s the difference between this bet and a quinella?
n × (n−1) combinations — while a quinella pays either order from one combination, so a quinella box is n × (n−1) ÷ 2. Both can be boxed with 3+ horses: a 3-horse box is 6 combinations here versus 3 for the quinella. The pools are separate, so compare probable payoffs on both boards before choosing.