What does the Random Number Generator do?

Generate random numbers within a range. Supports multiple numbers with or without duplicates. All calculations are performed in your browser using official UK rates and thresholds.

Is this calculator free to use?

Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.

Can I use this on my phone?

Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.

Random Number Generator

Generate random numbers within a range. Supports multiple numbers with or without duplicates.

Last updated: April 2026 · Source: National Lottery — Lotto

Minimum

Maximum

How Many

No duplicates (unique numbers only)

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

This tool generates random numbers within a range you specify. It uses a cryptographically secure pseudorandom number generator (CSPRNG) to ensure results are fair and unbiased. You can generate a single number or a set of multiple numbers, with or without repetition.

Common uses include raffle draws, lottery number selection, random sampling for surveys, assigning random groups and settling decisions fairly. The generator can also produce random dice rolls, coin flips and card draws with correct probability distributions.

Example: Generating lottery numbers

Range: 1 to 59 (UK Lotto)
Quantity: 6 numbers, no repeats
Result: e.g. 7, 14, 22, 35, 41, 53
Each draw is independent and equally likely

Source: National Lottery — Lotto

Frequently Asked Questions

What does the Random Number Generator do?: Generate random numbers within a range. Supports multiple numbers with or without duplicates. All calculations are performed in your browser using official UK rates and thresholds.
Is this calculator free to use?: Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.
Can I use this on my phone?: Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.