Free Linguistics Tools & Calculators

How to use these linguistics calculators

These tools cover quantitative analysis tasks across all levels of linguistic structure - from phoneme frequency to discourse readability. Whether you are a speech-language pathologist tracking a child's MLU development, a plain language editor checking Flesch-Kincaid scores, or a computational linguist running corpus statistics, each calculator uses established formulas and clinical norms from published research.

Readability and plain language

The readability suite includes Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index, SMOG Index, and Coleman-Liau Index - five different formulas each with strengths for different text types. US federal agencies are required by the Plain Writing Act of 2010 to use plain language in public-facing documents, and the Flesch-Kincaid Grade Level 8 or below is a common internal target. Libraries use readability scores to level collections and match readers with appropriate material. The plain language checklist tool goes beyond formulas to flag passive voice, nominalisations, and jargon that metrics miss.

Language acquisition and clinical tools

Mean Length of Utterance (MLU) is the single most widely used measure of grammatical development in child language research and clinical practice. The MLU calculator follows Brown's Stage scoring conventions and compares results against age norms from published databases. The language acquisition milestone tracker uses CDC and ASHA developmental norms to flag whether a child's vocabulary and grammar growth is on track. These tools are used by speech-language pathologists, educational technology developers building language learning assessments, and researchers studying bilingual acquisition. The bilingual language balance tool estimates relative dominance across two languages from response time and vocabulary data.

Corpus linguistics and translation

Type-token ratio, MATTR, and MTLD all measure lexical diversity but with different sensitivity to text length - the corpus statistics tool explains which measure to use for a given research question. Zipf's Law frequency distribution analysis reveals whether a corpus follows the expected rank-frequency relationship, a diagnostic used in corpus validation. These statistical tools are foundational for translation memory system development, terminology extraction, and the frequency-based vocabulary lists used in language learning platforms.