Lottery Combination Calculator

Order Matters More Than It Seems

Whether you're counting lottery number groups, arranging a shortlist, or seating a committee, the same question keeps coming up: does the order of selection matter? If it doesn't — picking 6 lottery numbers is the same set regardless of the order they're drawn in — you're counting combinations. If it does — a race's 1st, 2nd, and 3rd place finishers are a different outcome depending on order — you're counting permutations. The two formulas differ by a factor that grows fast, and mixing them up leads to wildly wrong counts.

The Formula

Combinations (order doesn't matter) = n! ÷ (r! × (n−r)!)
Permutations (order matters) = n! ÷ (n−r)!

Permutations count every distinct ordering of a selection separately, while combinations group all orderings of the same selection into one count — which is why permutations of the same n and r are always equal to or larger than combinations.

Where This Matters

  • Lottery number pools — standard lottery drawings use combinations, since the numbers on your ticket match regardless of the order they were physically drawn in.
  • Ranked outcomes — contests with distinct 1st/2nd/3rd place prizes, or any scenario where position matters, require permutations instead.
  • Verifying odds claims — if you've seen two different total counts quoted for the same n and r, checking whether each used combinations or permutations usually explains the discrepancy.
Combinations vs. permutations for the same n and r
n (pool)r (picked)CombinationsPermutations
49613,983,81610,068,347,520
103120720
661720

Notice that with n = r = 6, there's only one combination (every element is selected, so there's only one possible group), but 720 permutations — every possible ordering of those same 6 elements.

How to Use This Calculator

  1. Enter the total numbers in the pool (n).
  2. Enter the numbers picked (r).
  3. Select whether order matters (permutations) or order doesn't matter (combinations).
  4. Select Calculate for the total count.

Related Calculations

Apply this directly to a lottery drawing with the Lottery Odds Calculator, or check official Powerball odds with the Powerball Odds Calculator.