Saved paytables: Classic, Low, Medium and High

These are the multipliers visible in the screenshots. The tables apply only to 10 selected numbers with 10 drawn from 40.

Every positive multiplier in these four tables exceeds 1×. Their uncapped any-payout and net-profit probabilities therefore match. That relationship may change if a cap reduces a return to or below the stake.

These returns exclude rakeback. Gamdom’s announcement explains its 100% offer through instant rakeback. The displayed multipliers alone return 98.7597%–99.0374%; they need not independently add up to the combined promotional return. The article does not give a credit formula for each Keno table, so the calculator does not automatically add a fixed 1% or label a calculated shortfall as an actual rakeback rate.

How instant rakeback changes total return

Game payouts and rakeback are separate components. The combined theoretical return equals payout RTP plus expected rakeback divided by eligible wagering. A table can return less than 100% through game outcomes while a separate credit brings the combined expectation to 100%.

The figures below show the extra expected credit mathematically needed to bring each displayed table to 100%, assuming a positive stake, unchanged multipliers and no cap. They are not published or observed Gamdom rakeback rates.

For example, adding a hypothetical flat 1% of wagering to the displayed Low table would give 99.7597% combined return, not exactly 100%. This illustrates why a 1% credit should not be assigned to every mode without its calculation rules.

Worked Gamdom payout examples

Each example uses 10 picks, a 40/10 draw and a $10 stake, before a payout cap or rakeback. The outcome is exactly the listed number of matches.

Classic with three matches returns $14 from a $10 stake, leaving $4 profit for that outcome. Across its full saved table, 100 rounds at $10 each have expected net result of about −$9.63 before rakeback. Actual session results can be far above or below this expectation.

RTP contribution by hit count

Each row is one exact-hit outcome. Its RTP contribution is probability × game payout ÷ stake. Any entered gross-return limit is included; rakeback is excluded.

How this calculator works

A fair draw samples ten different numbers without replacement. If you pick n numbers, the chance of exactly h matches follows the hypergeometric distribution:

P(H = h) = C(n, h) × C(40 − n, 10 − h) / C(40, 10)

C(a, b) counts the ways to select b items from a. “At least h” adds the exact probabilities from h through n. “Match every picked number” uses h = n.

With 10 picks, a perfect 10-match draw has a probability of 1 in 847,660,528. This is a probability of matches, not proof of a particular prize. A seven-pick ticket has an expected 1.75 matches per draw, but individual rounds still produce whole-number outcomes from zero to seven.

Number patterns, recent draws and a previous losing streak do not change these probabilities under independent fair draws. Fewer picks make a complete match more likely; whether that ticket is more likely to pay anything depends on its paytable.

Zero Edge calculator — return including rakeback

This scenario uses Gamdom’s stated combined 100% return for eligible wagering, including instant rakeback, and the panel’s stated 99% return after the allowance. Enter total wagering within one allowance period and its eligible portion. Wagering is the sum of stakes placed, including money wagered again after a payout. This is the stated-rate model, not a calculation of the actual credit paid on each saved table.

Use the eligible amount available to your account. This calculation does not determine eligibility, split a bet across the allowance boundary, apply payout caps or schedule a reset. It does not calculate how individual rakeback credits are rounded or settled.

How the calculation works

Let T be total wagering and E its eligible portion. Expected net result is −0.01 × (T − E). For positive turnover, combined RTP is [E + 0.99 × (T − E)] ÷ T. The risk mode does not enter this model because it uses stated aggregate RTP rather than a reconstructed paytable.

These are mathematical expectations over repeated outcomes. They do not describe a typical session or the probability of finishing ahead. No wager is needed to use either calculator.

Odds for other pick counts

Choose how many numbers you pick and the number of matches to examine. These are match probabilities. A paying result depends on the multiplier table for your risk mode and pick count.

A match probability is not the same as a profit probability. For 10 picks, use the saved-table calculator above. For another pick count, use the paytable analyzer with its complete table. The 10-pick multipliers are not transferred to other ticket sizes.

Gamdom Keno rules, RTP and limits

The game description and the Zero Edge window describe different limits. Keep the game’s stake limits separate from the conditions for zero-edge wagering.

Gamdom’s announcement identifies instant rakeback as the mechanism behind the 100% offer. Its exact calculation for each Keno table is not specified in that text. The saved tables therefore show payout-only returns; the Zero Edge scenario uses the stated combined rates. A flat 1% of wagering is not assumed to be the actual credit for every mode.

Risk modes, payouts and practical controls

Why a 100% RTP game can still lose money in a session

RTP is an average across outcomes. A table can concentrate much of that return into rare prizes, leaving many sessions below their starting balance. Zero theoretical house edge does not make returns stable or guarantee a positive result after a fixed number of rounds.

The saved-table calculator gives one-round expected value and payout probabilities. The separate Zero Edge scenario uses stated aggregate rates; neither predicts bankroll depletion or the chance of a losing session. See Keno risk for repeated-round probability tools and Keno strategy for the limits of number selection and betting systems.

Provably fair controls

The Gamdom verification interface shows a client seed, a hashed server seed, a nonce, seed-change controls and a “Verify Result” button. These are starting points for reviewing a completed draw.

A server-seed hash alone is not enough to reproduce a draw. Independent verification requires the relevant revealed seed and Gamdom’s exact algorithm, together with its other required inputs. A verification panel does not establish the paytable’s RTP or prove that a session will be profitable.

Related Keno calculators

Sources and calculation scope

Reviewed 11 September 2026. Game details use supplied copies of the Gamdom Keno description and its 100% RTP announcement, plus screenshots of the game, help, verification, Zero Edge and four 10-pick paytables. The table screens show a zero-dollar bet and a demo notice. Their multipliers are transcribed as displayed; payout calculations exclude rakeback. These are saved references, not a live feed.

• Gamdom Keno and Gamdom Originals: official destinations for checking the current game and its rules.
• Gamdom announcement, Play ALL Gamdom Originals Games at 100% RTP: supplied article text describing instant rakeback on the first $5,000 wagered daily. The text does not specify a Keno credit formula by mode.
• SciPy hypergeometric distribution reference: the model for sampling without replacement.

KenoCalc is an independent mathematical reference and is not operated by Gamdom. Use only where lawful and at the applicable legal age. See Responsible Gambling for support information.