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Coin Flip Probability Calculator

Result

Calculated result 0.24609375 Based on the values entered.
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Coin Flip Probability Calculator — free online calculator.

Formula

P(X=k) = C(n,k) × (0.5)^n
  • Coin Flip Probability Calculator calculates its result from Flips, Heads. It uses the formula P(X=k) = C(n,k) × (0.5)^n. Change any input to recalculate the result instantly.
  • The main inputs are Flips, Heads. Enter them in the units and format shown in the calculator.
  • Keep comparable quantities in compatible units whenever the formula combines or compares them.
  • Changing any input above recalculates the result with the same calculation engine used by this page.

Example: Coin Flip Probability

Inputs
  • Flips: 10
  • Heads: 5

Using Flips = 10, Heads = 5, the calculated result is 0.24609375.

Sample result: Calculating…

Frequently asked questions

What does the Coin Flip Probability calculate?

Coin Flip Probability Calculator — free online calculator.

Which values should I enter?

Enter Flips, Heads using the units and format shown beside each field.

What formula does this calculator use?

The calculator uses the following relationship: P(X=k) = C(n,k) × (0.5)^n.

Why might my result differ from another source?

Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.

Does the result update automatically?

Yes. Changing an input updates the result using the same calculation engine shown on this page.

Page information

Updated: October 7, 2026