This tool will calculate the complexity of your text based on the Kuperman Age-of-Acquisition ratings based on about 30 000 English words (nouns, verbs, and adjectives). The higher the score the more complex the results. Why? Complexity in terms of words may be a good indicator of understanding of words. The thing is, sometimes we use words that we might consider is well-understood by others but that is simply not true. If English is not your first language then more complex words might rather be due to the fact that the native language correlate of the same word is well understood but not the English word of the same. Another reason might be the level of education, age and other factor's which might be harmful in terms of your own writing. Meaning, if your audience consists of people who are below a certain age then having a complex formulation of your writing may not come across as you intended since much of it will not be understood. In short this tool helps you to fine-tune your results to fit with the understanding of your target group