Bloom Filter Calculator

Calculate Bloom filter bit size and hash count from expected items and false-positive rate.

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Enter the example value or paste your own input, choose the mode when one is available, and read the first result card for the direct answer. The output area gives a copyable block for code reviews, documentation, API tests, classwork or troubleshooting notes.

What the result means

The calculator uses the standard Bloom filter formulas for optimal bit array size and hash count.

What is not included

It assumes ideal independent hashes and does not model deletions. Counting Bloom filters need more storage.

Privacy note

The calculation runs in your browser. Avoid pasting production secrets, credentials, private keys, customer data or regulated personal data unless your own policy allows browser-based tools.