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Loto 7 (Japan): a game guide
Loto 7 is Loto 6's sister game: you choose seven distinct numbers from 1 to 37. With one more number and a smaller pool, it has more jackpot combinations than Loto 6. It has two bonus numbers rather than one, six prize tiers, and a 2025 revision of prizes that put the first prize at JPY 700 million when there is no carryover. This guide works out the structure by exact calculation and keeps clearly apart the effect of tier 6, whose condition we could not confirm. In this site's verification registry, the number format, price and draw day were confirmed and a numeric official odds figure was not.
- Format
- 7 numbers from 37; two draw-only bonus numbers verified
- Price
- JPY 300 per line verified
- Draw day
- Friday verified
- Jackpot combinations
- 10,295,472 = C(37,7) (calculated; no official odds figure established) computed by LottoFlick
- Prize amounts (theoretical)
- 1st JPY 700 million (from round 613, 14 Feb 2025); 2nd about JPY 6.1 million; 3rd JPY 500,000; 4th JPY 6,500; 5th JPY 1,400; 6th JPY 1,000 partly verified
- Carryover cap
- JPY 1.2 billion when a carryover has occurred partly verified
- Tier 6 condition
- Uses a bonus number; exact condition not confirmed not verified
- Supported in this site's tools
- Yes: generator, Lottery Explorer, Combination Calculator and Lab computed by LottoFlick
The numbers: 10,295,472 combinations
There are C(37,7) = 10,295,472 ways to choose seven distinct numbers from 37 without order, about 26% more than Lotto 6/45 (8,145,060) and about 1.7 times Loto 6 (6,096,454). A line has a 1 in 10,295,472 chance of the first prize; the figure is calculated from the number format, not confirmed as an official odds figure. The two bonus numbers are drawn only in the draw and not chosen by the player, so they do not affect the number of jackpot combinations.
The distinctive structure: two bonus numbers decide the second and sixth tiers
From a search summary of the official site, the draw fixes seven main numbers and two bonus numbers, and the bonus numbers are used only to decide the second and sixth tiers. Tiers 1 to 5 and their exact odds are:
| Tier | Condition | Prize (theoretical) | Winning tickets | Odds (1 in N) |
|---|---|---|---|---|
| 1st | 7 main numbers | JPY 700 million | 1 | 10,295,472 |
| 2nd | 6 main numbers + at least one bonus number | about JPY 6.1 million | 14 | 735,390.9 |
| 3rd | 6 main numbers | JPY 500,000 | 196 | 52,527.9 |
| 4th | 5 main numbers | JPY 6,500 | 9,135 | 1,127.0 |
| 5th | 4 main numbers | JPY 1,400 | 142,100 | 72.5 |
| 6th | uses a bonus number (exact condition not confirmed) | JPY 1,000 | not calculated | - |
The counts work like this. The 2nd tier is six of the seven main numbers plus the remaining number being one of the two bonus numbers: C(7,6) × 2 = 14. The 3rd tier is six main numbers and one of the 28 numbers that are neither main nor bonus: 7 × 28 = 196. The 4th is C(7,5) × C(30,2) = 9,135 and the 5th C(7,4) × C(30,3) = 142,100 (30 numbers are non-main, two of which are bonus). We followed the notice that a ticket qualifying for several tiers is paid in the highest.
The tier-six problem: an unconfirmed condition
The notice mentions tier 6 as a tier using a bonus number, but we could not confirm its exact condition, so the table does not calculate tier 6's odds. If we assume the commonly stated condition ("3 main numbers and at least one bonus number"), the count is as follows. Three main numbers match and the other four numbers come from the 30 non-main numbers with at least one of them a bonus number: C(7,3) × (C(30,4) − C(28,4)) = 35 × 6,930 = 242,550 tickets. If this assumption is right, tier 6 is 1 in 42.4 and the chance of any prize is about 3.83% (1 in 26.1). These are calculations resting on an assumption and not established facts.
The 2025 prize revision
According to the official site's notice (via a search summary), Loto 7's prizes were revised from round 613 (the draw of 14 February 2025): the first prize without a carryover went from JPY 600 million to JPY 700 million, and the maximum after a carryover from JPY 1 billion to JPY 1.2 billion. Some pages still carry the earlier figures (JPY 600 million, JPY 1 billion), so it is easy to confuse old material. This guide uses the post-revision values and mentions the earlier ones for reference only. How the other tiers' amounts were adjusted along with the larger first prize we could not confirm.
The return implied by the prize amounts
Multiplying the theoretical prizes by the exact odds and adding gives:
- 1st: JPY 700 million ÷ 10,295,472 ≈ JPY 68.0
- 2nd: about JPY 6.1 million × 14 ÷ 10,295,472 ≈ JPY 8.3
- 3rd: JPY 500,000 × 196 ÷ 10,295,472 ≈ JPY 9.5
- 4th: JPY 6,500 × 9,135 ÷ 10,295,472 ≈ JPY 5.8
- 5th: JPY 1,400 × 142,100 ÷ 10,295,472 ≈ JPY 19.3
Tiers 1 to 5 total about JPY 110.9, 37.0% of the JPY 300 price. Adding the assumed tier 6 (JPY 1,000 × 242,550 ÷ 10,295,472 ≈ JPY 23.6) gives about JPY 134.5, 44.8%. That the total with tier 6 is almost the same as Loto 6's 44.95% is circumstantial support for the assumed tier-6 condition, but it is only circumstantial and the condition is not confirmed. We did not confirm an official prize share for Loto 7 alone.
Compared with its Japanese sibling Loto 6
| Item | Loto 7 | Loto 6 |
|---|---|---|
| Pool and picks | 7 from 37 | 6 from 43 |
| Jackpot combinations | 10,295,472 | 6,096,454 |
| Bonus numbers | 2 (2nd and 6th tiers) | 1 (2nd tier) |
| Draw | every Friday | Monday and Thursday |
| Price per line | JPY 300 | JPY 200 |
| First prize without carryover | JPY 700 million | JPY 200 million |
| Top first prize after a carryover | JPY 1.2 billion | JPY 600 million |
Loto 7 aims for a larger prize at once at the cost of a harder first prize. The price is 1.5 times (JPY 300 against JPY 200) but the first prize without a carryover is 3.5 times. Multiplying "how large the prize is" by "how low the probability is" (expected value) is the basis for understanding the structure of a lottery. The concept is covered in Why do people buy lottery tickets with negative expected value?.
Worked examples: what 10,295,472 means in practice
With p = 1/10,295,472 for the first prize, three exact calculations give a sense of scale.
- A coin flip. At least one first prize with probability 50% needs ln 2 × 10,295,472 ≈ 7.14 million lines. At JPY 300 a line that is about JPY 2.14 billion, three times the JPY 700 million first prize without a carryover, and still only an even chance.
- Weekly for 50 years. The single weekly draw gives about 2,600 draws in fifty years. One line each time gives a lifetime chance of about 0.025% of a first-prize ticket, or 1 in 3,960, at a total cost of JPY 780,000. Over those 2,600 lines the fifth tier (1 in 72.5) is expected about 36 times.
- A hundred lines in one draw. The first-prize chance for that draw is 100 in 10,295,472, roughly 1 in 103,000.
The scale is why this game's structure leans on large prizes: a rare first prize paying JPY 700 million, and up to JPY 1.2 billion after a carryover, balances a pool of 10 million combinations.
A caution when reading the figures
The return rate with the assumed tier 6 (44.8%) and without it (37.0%) differ by 7.8 percentage points. Not knowing one condition moves the conclusion that far, which is a lesson in itself. For the same reason, comparison tables on the internet can give a wrong ranking when a tier-six condition or a rollover rule is missing. This guide separates what is confirmed (tiers 1 to 5) from what is assumed (tier 6) in the table itself, and a reader comparing it with another site should ask which cells are confirmed. How big numbers and return rates blur judgement is covered in why big numbers blur our judgement.
On this site
- The Lottery Explorer shows Loto 7's verification status.
- The Combination Calculator shows the C(37,7) calculation.
- In the Lottery Lab you can simulate draws in this format.
- The number generator draws seven distinct numbers from 37 at random; it does not improve the chance of winning.
What we could not verify
- The exact condition and odds of tier 6 (the calculation above is an assumption).
- An official odds table (the odds here are calculated).
- How the 2025 revision adjusted the other tiers, and details of the carryover rules.
- The prize share of sales for Loto 7 alone, tax treatment and the payment deadline.
- Mizuho Bank's page refused access when re-read on 25 October 2026, so the number format, price and draw day use the registry's 4 October review as it stands.
Lottery outcomes are random, and understanding odds does not change the probability of a particular ticket. Set a spending limit and check local age and participation restrictions. This site does not sell lottery tickets.
LottoFlick is independent and not an official lottery operator. Numbers are random and cannot be predicted.
Sources and verification
- Mizuho Bank (lottery trustee), Loto 7: seven of 37, two draw-only bonuses, JPY 300, Friday (as reviewed in the registry on 2026-10-04) — verified · the page returned HTTP 403 to a later fetch on 2026-10-25
- Takarakuji official site, Loto 7 features: tier conditions and theoretical prizes, including the revision from round 613 (seen through a search summary on 2026-10-25) — partly verified · the page itself was not opened
- LottoFlick calculation: exact tier counts and the implied return — computed by LottoFlick