Calculate Your Lucky 15 Manually

A Lucky 15 is one of the most popular horse racing bets in the UK. It covers four selections in 15 different bets: 4 singles, 6 doubles, 4 trebles, and 1 fourfold accumulator.

Most punters use a calculator because the maths quickly gets complicated… but you can work it out by hand if you understand the structure. This guide shows you exactly how to calculate a Lucky 15 (and even other bet types) manually, step by step, if you really want to!

Step 1: Write out the 15 bets

The first thing you need is a list of the actual bet lines. Without this, you’ll miss something when calculating. For four horses (A, B, C, D), your Lucky 15 looks like this:

Singles (4):

• A
• B
• C
• D

Doubles (6):

• AB
• AC
• AD
• BC
• BD
• CD

Trebles (4):

• ABC
• ABD
• ACD
• BCD

Fourfold (1):

• ABCD

That’s your full map of the 15 bets.

Tip: Write them down on paper before you even place the bet. Then you can tick them off later when working out returns.

Step 2: Convert the odds to decimal

Fractional odds (like 5/2 or 7/4) are traditionally used in the Uk, but decimals make multiplying much easier.

The formula is simple:

Decimal odds = (numerator ÷ denominator) + 1

Examples:

• 2/1 → 3.00
• 5/2 → 3.50
• 7/4 → 2.75
• 9/2 → 5.50

Tip: Write all your selections in decimal odds before you start. It will save you time and errors.

Step 3: Work out your stake per line

In a Lucky 15, each of the 15 bets is a separate line with its own stake.

• If you bet £1 per line → total stake is £15
• If you bet £2 per line → total stake is £30
• If you bet 50p per line → total stake is £7.50

Tip: Many new punters think a “£1 Lucky 15” means £1 in total. It doesn’t. It means £1 on each of the 15 lines, so £15 total.

Step 4: Identify which selections won

When the races are done, mark which horses won and which lost. This will tell you which lines are live.

• If a line contains a losing horse → that line returns £0.
• If all the horses in the line won → calculate the return for that line.

Step 5: Calculate each winning line

Now, for each line that won:

1. Multiply the decimal odds of each horse in that line.
2. Multiply the result by your stake for that line.
3. Write the return next to that line.

Example: Three winners (A, B and D win; C loses)

Odds (converted to decimal):

• A = 2/1 → 3.00
• B = 5/2 → 3.50
• C = 7/4 → 2.75
• D = 9/2 → 5.50

Stake: £1 per line = £15 total.

Now calculate line by line:

Singles:

• A: 3.00 × £1 = £3.00
• B: 3.50 × £1 = £3.50
• C: £0.00
• D: 5.50 × £1 = £5.50 Subtotal = £12.00

Doubles:

• AB: 3.00 × 3.50 × £1 = £10.50
• AC: loses (C lost)
• AD: 3.00 × 5.50 × £1 = £16.50
• BC: loses
• BD: 3.50 × 5.50 × £1 = £19.25
• CD: loses Subtotal = £46.25

Trebles:

• ABC: loses
• ABD: 3.00 × 3.50 × 5.50 × £1 = £57.75
• ACD: loses
• BCD: loses Subtotal = £57.75

Fourfold:

• ABCD: loses (C lost) Subtotal = £0.00

Step 6: Add it all up

Add the winning lines:

• Singles = £12.00
• Doubles = £46.25
• Treble = £57.75
• Fourfold = £0.00

Total return = £116.00

Profit = £116 − £15 stake = +£101.00

Step 7: Adjust for bonuses or Rule 4 (if applicable)

• One-winner consolation: Some bookies double the odds if only one horse wins. Apply this to the single.
• All-winners bonus: Some bookies add 10% to the total if all four win. Add it at the end.
• Rule 4 deductions: If a horse is withdrawn, reduce the odds on affected lines before multiplying.

What about an each-way Lucky 15?

If your bet was each-way, everything above is doubled:

• 30 bets total (15 win + 15 place).
• Place terms apply (e.g., 1/5 the odds for 3 places).
• Winners also count as placed, so you get both.

You simply repeat the whole calculation with reduced place odds, then add the win and place returns together.

Final Thoughts

Manually calculating a Lucky 15 is a lot of work, but it’s possible if you break it into steps:

1. List the lines.
2. Convert the odds.
3. Work out the stake.
4. Identify winners.
5. Multiply for each line.
6. Add up the returns.
7. Apply bonuses/deductions.

It’s slow but straightforward. Once you’ve done it once, you’ll appreciate why most punters prefer using a Lucky 15 Calculator, it does all this instantly and without mistakes.