Saturday Lotto Odds Calculator

Saturday Lotto — TattsLotto in Victoria, Gold Lotto in Queensland, X Lotto in South Australia, Lotto elsewhere — is the 6-from-45 national draw. Defaults: Tickets 1, Ticket Price AU$0.80, Jackpot 1,000,000, Main Matches 6. There is no Bonus Matches box because this calculator prices Division 1 as 6/45 only. Calculate: Jackpot Odds 1 in 8,145,060, which is 1/C(45,6). That is roughly 7.7 times softer than Oz Lotto’s 7/47 and about 16.5 times softer than Australian Powerball’s 7/35+1/20. At an $80-cent line and a $1 million default pool, Jackpot EV is about −AU$0.68: you spend 80 cents to buy an expected jackpot return near 12 cents.

Set Main Matches to 5. This Prize Odds jump to about 1 in 34,808 for exactly five of the six drawn mains. That is not Division 2 in the official table, because real Saturday Lotto also draws two supplementary numbers from the remaining 39 balls; five mains plus a supplementary is a different division from five mains alone. This page will not simulate those supplementary balls. Use Main Matches as “how many of the six winning mains sit on my line,” nothing else.

Tickets at 10 leaves price at $0.80 and jackpot at a million: Chance becomes 1−(1−1/8,145,060)^10≈1.23×10^−6, EV about −AU$6.77. A Saturday family syndicate that always buys the same 12-game QuickPick block should enter 12. Counting “one playslip” as one ticket understates both cost and chance if the slip holds multiple games. Price is 80 cents per standard game; Monday and Wednesday Lotto are different products with different pools even when they also use 6/45.

Jackpot defaults to AU$1,000,000 because that is a typical Division 1 neighbourhood on a quiet Saturday, not a record roll. Paste the actual advertised Division 1 from The Lott. Guaranteed minimums and jackpot rising in $1 million-ish steps are a Saturday Lotto habit; EV at $5 million is still 5,000,000/8,145,060−0.80≈0.61−0.80=−0.19, negative but far less ugly than Oz Lotto at $3 million. Sharing risk grows when the whole east coast buys the same birthday numbers.

Work top-down: confirm you are not on the Oz Lotto or Powerball calculator, set Tickets to games not people, set Price to 0.80 unless you have a bundle convention, paste Jackpot, set Main Matches to 6 for Division 1 or 4–5 to inspect hypergeometric consolation probabilities, then read EV as jackpot-only.

TattsLotto was first drawn in Victoria on 24 June 1972, a Saturday night 6-from-45 that became the template for Australia’s weekend lottery. Over the following decades the same draw was branded Gold Lotto, X Lotto, or simply Lotto depending on the state, while the balls stayed 6/45 with two supplementary numbers. That branding patchwork still confuses visitors: there is one Saturday night combination, sold under several shop names, now under The Lottery Corporation / The Lott. It is the cheap, familiar cousin of Tuesday Oz Lotto and Thursday Powerball, and it is the game grandparents still call “the lotto.”

Eighty cents a game is the cultural hook. You can buy a Saturday night out of coin tray change. That cheapness is why Division 1 odds of 1 in 8.15 million feel “reasonable” next to Powerball’s 134 million and why newsagents sell mountains of Saturday games relative to Tuesday’s $2.50 Oz lines. Pari-mutuel Division 1 still splits, still rolls, and still publishes guaranteed floors. A million-dollar Saturday is ordinary; a multi-ten-million Saturday is a roll story, not a different matrix.

Two supplementary numbers decide most of the prize chart. Division 1 is six mains. Lower divisions mix five mains plus a supplementary, five mains, four plus a supplementary, and so on. This calculator does not take supplementary inputs. If you are arguing in a pub about whether five numbers plus the supplementary is “almost the jackpot,” the answer is combinatorially no: you were never in the C(45,6) singleton, you were in a much larger hypergeometric cell, and the supplementary only moves you between lower divisions.

1972 Victoria is the origin myth; nationalisation is the present. Monday and Wednesday Lotto recycle the 6/45 feel on weekdays with separate prize funds. Do not paste a Wednesday jackpot into this Saturday form and expect the EV to mean anything about Saturday night. Same combinatorics, different money.

Use this page to price a Saturday 6/45 jackpot, to see why 80 cents times eight million combinations is still a negative-EV product at ordinary pools, and to stop mixing TattsLotto with Oz Lotto because both are “Australian lotto.” One is 6/45 on Saturday. The other is 7/47 on Tuesday. The supplementary balls are real-world colour; they are not fields on this calculator.

The Division 1 prize of Saturday Lotto — Tattslotto in Victoria, Gold Lotto in Queensland, X Lotto in South Australia — is calculated as six unordered numbers from forty-five. Combinations: C(45,6) = 45 × 44 × 43 × 42 × 41 × 40 / 720. The falling product is 5,864,443,200; divide by 720 to obtain 8,145,060. Single-game jackpot probability is 1 / 8,145,060, about 1.228 × 10^−7, or one in 8,145,060. That is roughly 7.7 times softer than Oz Lotto's 7/47 and about 16.5 times softer than Australian Powerball's 7/35 plus 1/20. Two supplementary numbers from the remaining thirty-nine balls decide most lower official divisions and do not enter this six-of-six identity. First drawn in Victoria on 24 June 1972, the weekend 6/45 remains the cheap national cousin of the midweek jackpots.

Hypergeometric overlap for a six-spot ticket is P(exactly m) = C(6,m) × C(39, 6−m) / 8,145,060. Matching five is 6 × 39 / 8,145,060 = 234 / 8,145,060, about one in 34,808. Matching four is 15 × 741 / 8,145,060 = 11,115 / 8,145,060, about one in 733. Matching three is 20 × 9,139 / 8,145,060 = 182,780 / 8,145,060, about one in 45. Official divisions that also demand a supplementary need an extra layer this jackpot lecture omits.

Independent Saturday games give at-least-once chance 1 − (1 − p)^n. Ten games sit near 1.23 × 10^−6. An eighty-game book at eighty cents still has only about a 9.82 × 10^−6 shot at Division 1. Covering the matrix at AU$0.80 would cost about $6.52 million.

Expectation uses the default eighty-cent game and a one-million advertised Division 1: 1,000,000 / 8,145,060 − 0.80 ≈ 0.123 − 0.80 = −$0.677 per game. Ten games: about −$6.77. Jackpot-only breakeven with one winner is 0.80 × 8,145,060 = AU$6,516,048. At a five-million pool the hole shrinks to about −$0.19, still negative. A fifty-game family book costs $40, has chance ≈ 6.14 × 10^−6, and expected value about −$33.86 at the million-dollar default. Doubling the advertised jackpot halves the loss per game; it does not send expected value to zero.

Assumptions: uniform six-subsets of forty-five, independent games, one winner, Australian dollars, $0.80 stake, supplementary balls omitted, and no Tuesday Oz Lotto or Thursday Powerball mixed into the Saturday count. Monday and Wednesday 6/45 products, when they exist, are separate prize funds with the same combinatorics and different money. Dutch and Austrian 6/45 games share C(45,6) and none of the Tattslotto branding.