Calculators & Generators

Coin Flip Simulator (Heads or Tails)

Flip once to decide, or flip many times to watch the law of large numbers.

By TheCalcTools Updated Formula checked and tested
Result
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Heads
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Tails
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Longest run of the same side
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Coin Flip Simulator (Heads or Tails) by TheCalcTools

How the Coin Flip Simulator (Heads or Tails) works

Each flip is independent with exactly a 50% chance of heads, drawn from your browser’s cryptographic random generator.

With many flips the share of heads settles near 50%, but streaks are longer than most people expect: in 100 flips, a run of 6 or more of the same side is common.

Worked example

Flipping 1,000 times typically gives between about 470 and 530 heads (two standard deviations), and the longest streak is usually 8 to 12.

Frequently asked questions

Is a real coin exactly 50/50?

Very nearly. Studies of real tosses suggest a slight bias towards the side that started facing up, about 51%.

What is the chance of 10 heads in a row?

1 in 1,024 (0.5¹⁰). Use the coin flip probability calculator for exact odds.

Sources and further reading

Coin Flip Probability CalculatorHow likely is it to get k heads in n flips? Dice Roller (d4, d6, d8, d10, d12, d20)Choose your dice and press Roll Random Number GeneratorPick a range and how many numbers you need, then press Generate Random Name Picker (Winner and List Shuffler)Paste a list, choose how many to pick, and press Pick Password Generator (Strong, Random, Private)Choose the length and character types; a new password appears instantly Random Team GeneratorPaste the players, choose the number of teams and press Make teams

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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.