Username Idea Count Calculator

Work out username idea count instantly with clear inputs, formula shown and shareable results.

About Username Idea Count Calculator

Independent choices multiply, so the total is base words times suffixes times numeric endings, and the entropy is the base-two logarithm of that product. The multiplication is why adding a two digit number to a name multiplies the options by a hundred, which is exactly why so many usernames end in numbers.

Formula

Combinations

total = base words x suffixes x numeric endings

Worked example

With the default values below, Username Idea Count Calculator returns Possible usernames of 10,000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Base words availableminimum 1: 5
Suffixes availableminimum 1: 20
Numeric endings availableminimum 1: 100

Results

Possible usernames: 10,000
Combinations without numeric endings: 100
Digits needed for the numeric range: 2
Entropy of the name space: 13.288 bits

Step by step

1Values used
2Combinations
3Possible usernames= 10,000
4Combinations without numeric endings= 100
5Digits needed for the numeric range= 2
6Entropy of the name space= 13.288 bits

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Username Idea Count figure worked out?

total = base words x suffixes x numeric endings. Independent choices multiply, so the total is base words times suffixes times numeric endings, and the entropy is the base-two logarithm of that product.

Why does this matter?

The multiplication is why adding a two digit number to a name multiplies the options by a hundred, which is exactly why so many usernames end in numbers.

What do I need to enter?

Enter base words available, suffixes available, numeric endings available. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.