CalcaTools

Random Sample Generator

Draws a simple random sample of any size from your pasted list, with or without replacement.

Last updated: June 2026 · Free · No sign-up required

Results

Enter values above and click Calculate to see your result instantly.

Quick reference

NeedSetting
Pick 1 winner from entriesSample size 1, without replacement
Survey 30 of 500 customersSample size 30, without replacement
Bootstrap resample of a datasetSample size = n, with replacement
Assign 10 people to 2 teamsSample 5, the rest form team 2

Interpretation guide

MethodWhen to use
Without replacementWinners, audits, surveys — each item can be picked once
With replacementBootstrapping and simulations — items can repeat

Formula & methodology

Formula: Each item is selected with equal probability; without replacement uses an unbiased Fisher–Yates shuffle

  1. Paste your population — one item per line or comma-separated.
  2. Choose how many to draw and whether items may repeat.
  3. The generator shuffles with the Fisher–Yates algorithm seeded by a cryptographically secure random source and returns the first n items.

Worked example: sampling 3 from a 10-name list gives every name an identical 3-in-10 chance of selection — a textbook simple random sample, free of the ordering bias you get by 'just picking a few'.

Frequently asked questions

How do I generate a random sample?
Paste your full list, enter the sample size, and click Calculate. The tool shuffles the list with the Fisher–Yates algorithm and returns the requested number of items, each with equal probability.
What is the difference between sampling with and without replacement?
Without replacement, an item can be drawn only once (winners, audits, surveys). With replacement, the same item can appear multiple times — required for bootstrap resampling in statistics.
Is this a true simple random sample?
Yes — every possible subset of the chosen size is equally likely, because the shuffle is unbiased and driven by a cryptographically secure random source rather than a predictable seed.
How large should my sample be?
For a population survey, around 370 of 10,000 gives ±5% margin at 95% confidence — use our sample size calculator for exact numbers. For drawings and audits, the size is set by your rules, not statistics.
Can I redraw the sample?
Yes — every click of Calculate performs a completely fresh, independent draw. There is no way to reproduce a previous draw, which is exactly what fairness requires.