Math & Statistics

Random Number Generator Calculator

Generate a reproducible pseudo-random number between two limits, with optional integer mode, seed, draw count and range-size proof.

Use calculator See formula Questions

Default example421 reproducible draw from 1 to 100. Seed 20,260,620; first values: 42. Not security-grade randomness.

Calculator

Working calculator

MinimumSmallest allowed value in the draw range.MaximumLargest allowed value in the draw range.SeedUse the same seed to reproduce the same result for audits, classroom examples or draws.Draw countNumber of reproducible draws to summarise.Integer modeChoose whole-number draws or decimal draws.

Live result421 reproducible draw from 1 to 100. Seed 20,260,620; first values: 42. Not security-grade randomness.

Formula used

Random fraction = seeded pseudo-random value in [0, 1). Decimal result = minimum + fraction × (maximum − minimum). Integer result = floor(minimum + fraction × (maximum − minimum + 1)).

This is the method behind the answer, so the result can be checked rather than simply trusted.

Visual grid

This number is one point on a larger pattern

Random Number Generator is not just a final answer. It is a step on a line: before and after, input and output, assumption and result.

Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars

InputFormulaResult

CalculationTime keeps the path visible: the input, the method and the final number belong together.

421 reproducible draw from 1 to 100. Seed 20,260,620; first values: 42. Not security-grade randomness.

Inputs

Minimum: 1
Maximum: 100
Seed: 20,260,620
Draw count: 1
Integer mode: Whole numbers

Method

Random fraction = seeded pseudo-random value in [0, 1). Decimal result = minimum + fraction × (maximum − minimum). Integer result = floor(minimum + fraction × (maximum − minimum + 1)).

For a 1 to 100 whole-number range, the seeded fraction is scaled across 100 possible integer outcomes, then floored to a visible draw.

Assumptions

The generator is deterministic for transparency and testing.
This page is not suitable for cryptography, gambling, lotteries or security-sensitive randomness.
Integer mode treats both endpoints as possible results.

Notes

Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.

Explain it like I'm 12

The random number generator maps a numeric seed into a repeatable pseudo-random fraction, then scales that fraction into the selected minimum-to-maximum range.

Source references

NIST Random Number Generation — official background on security-grade random generation, cited as a boundary for this non-security tool

Formula

Random fraction = seeded pseudo-random value in [0, 1). Decimal result = minimum + fraction × (maximum − minimum). Integer result = floor(minimum + fraction × (maximum − minimum + 1)).

Worked example

For a 1 to 100 whole-number range, the seeded fraction is scaled across 100 possible integer outcomes, then floored to a visible draw.

Professional note

Master’s Tip: save the seed beside any published draw so another person can reproduce the same number path.

Regional and unit assumptions

Standard basis: transparent pseudo-random arithmetic for educational, planning and demonstration uses.

Assumptions and limitations

The generator is deterministic for transparency and testing.
This page is not suitable for cryptography, gambling, lotteries or security-sensitive randomness.
Integer mode treats both endpoints as possible results.

Methodology & Accuracy

How this calculator is checked

CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.

Formula used

Random fraction = seeded pseudo-random value in [0, 1). Decimal result = minimum + fraction × (maximum − minimum). Integer result = floor(minimum + fraction × (maximum − minimum + 1)).

Standard or basis

Standard basis: transparent pseudo-random arithmetic for educational, planning and demonstration uses.

Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.

Master's Tip

Master’s Tip: save the seed beside any published draw so another person can reproduce the same number path.

Related calculators

Questions

Is this cryptographically secure?

No. It is a transparent reproducible generator, not a security or gambling random source.

Why does the seed matter?

The same seed recreates the same output, which makes classroom examples and audit notes easier to check.