Dice Coefficient Calculator

Calculate the Dice coefficient

The Sorensen-Dice coefficient is a measure of similarity between two sets, equal to twice the number of elements they share divided by the total number of elements in both. This calculator treats each text as a set of unique words and computes the coefficient, which ranges from zero for no overlap to one for identical sets. Two texts of three words each that share two words have a Dice coefficient of two thirds.

It is closely related to the Jaccard index but weights the shared elements more heavily, which often makes it more forgiving for short texts.

Dice versus Jaccard

The Dice and Jaccard coefficients always rank pairs of sets in the same order, but Dice gives higher values for the same overlap because it counts the shared elements in both the numerator twice and the denominator. The Dice coefficient is popular in natural language processing, image segmentation evaluation and bioinformatics. A common refinement uses character bigrams instead of words to capture spelling similarity.

Choose Dice when you want a similarity that emphasises overlap, and Jaccard when you prefer the stricter union-based measure. All calculation happens locally in your browser.

Related tools

• AI Prompt Leakage Analyzer — Paste a system prompt and a hostile user input to see whether the prompt holds secrets and whether the input carries injection patterns. Local, instant.
• LLM Data Exposure Checker — Check if text contains data likely to be memorized or exposed by LLMs.
• AI Usage Policy Generator — Generate an acceptable use policy for AI tools in your company.
• Model Hallucination Estimator — Estimate risk of hallucinations based on task type and temperature.