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Number Generators

Random Numbers That Sum To a Target

Generate a set of random numbers that add up to the exact total you specify.

Random Numbers That Sum To a Target

20, 35, 12, 8, 25

5 numbers · sum 100

How many numbers and target sum

The numbers will add up exactly to the target

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How to use the sum to target generator

  1. Set how many numbers you want and the exact total they must reach.
  2. Optionally bound each number with a minimum and a maximum.
  3. Press Generate numbers. The set always lands exactly on the target.

How many ways a total can be split

Splitting a target into parts is a classic counting problem, and the number of possible ordered splits grows explosively. For a target of 100 with parts allowed from 0 to 100, the counts are:

PartsPossible ordered splits of 100
2101
35,151
4176,851
54,598,126
104,263,421,511,271

Combinatorics calls these figures compositions, counted by the stars and bars formula. Ten parts already allow over four trillion different splits of 100, which is why two presses of the button essentially never repeat.

When the target is impossible

The count and the per number bounds set hard limits: the smallest reachable total is the minimum times the count, and the largest is the maximum times the count. Ask for five numbers between 0 and 10 that total 100 and no answer exists, since five tens only reach 50. The tool checks this before drawing and tells you the reachable band, so you can widen the bounds or change the count instead of getting a silently wrong set.

Where a fixed total draw is used

This draw pattern appears wherever a whole must be shared randomly: splitting a marketing budget across five channels for a scenario test, sharing 100 quiz points across rounds, generating invoice lines that must reconcile to a known total, allocating a fixed stock across bins, or building spreadsheet test data whose sum column is already agreed. Each press gives a fresh split with the total guaranteed, and the per number bounds keep any single share from dominating.

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Frequently asked questions

How can random numbers add up to a set total

The tool shares the target across the count you ask for. Each number is drawn within its allowed range, and the last values are constrained so the set always lands exactly on the target.

Can I control how big each number is

Yes. Set a minimum and a maximum per number. If the target cannot be reached within those limits, the tool tells you the total range that is possible.

Why does it say the target is not possible

Because the count and the per number limits cannot reach it. For example five numbers each 0 to 10 can only total between 0 and 50.

Are the numbers whole

Yes, every value is a whole number and the set adds up to the exact target you set.

Is it free

Yes, free and with no sign up. Every draw runs in your browser and nothing you enter leaves your device.

Related generators

Need an ordinary draw instead? The random number generator picks numbers with no total constraint, and the random sample generator selects items from a list.