An exacta box calculator tells you what a boxed exacta will cost before you hand over the money. Box three horses for $2 and you’re buying six combinations, so $12. Box four and it’s twelve combinations, $24. The free calculator above does boxes, keys and straight exactas, and it shows what the same horses would cost as a trifecta box.
How the exacta box calculator works
An exacta pays when you name the first two finishers in the right order. Boxing covers both orders for every pair of your horses.
Exacta box = n × (n − 1) Exacta key = horses under your key horse Cost = combinations × base bet
Here’s the bit people miss. A box doesn’t pay several times when it hits: only one order can come in. So a $2 three-horse box costs $12 and returns one $2 exacta payout. If that exacta pays $18, you’ve made $6. The payout needs to be at least the box size times the base bet before a boxed exacta shows a profit.
Box, key or straight?
If you’re sure about the winner, a key is cheaper: your top pick over three others is three combinations, $6, against $24 for a four-horse box. If you’re torn on the order between two horses, a two-horse box ($4) covers both. And if you’re confident about both the winner and the runner-up, a straight $2 exacta gives you the full payout for the minimum.
In the UK and Ireland the same bet is a forecast, and the boxed version is a reverse forecast. For the top three or four, use the trifecta calculator or the superfecta calculator.
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