Readability signifies easy comprehension of the text by a reader. There are three main aspects of readability: legibility of the text, easy flow of reading and easy comprehension. Thus, readability of a book is dependent on many factors, such as clarity of presentation in terms of language and illustration as also the ability of a reader in terms of his/her intellectual level, language proficiency and mental alertness. All authors may not have equal capability to produce 'readable' books. But they can certainly improve the readability of their books if they are able to know the readability level of the manuscripts that they have produced. For this, several experts have devised readability formulas to measure the readability of any text. Measurement of readability refers to the process of assessing the extent of ease in reading and understanding a written text. Most readability formulas are based on one semantic factor, i.e., the difficulty of words and one syntactic factor, i.e., the difficulty of sentences. These formulas assume that longer sentences are harder sentences and longer words are harder words. Each readability formula measures text differently, but each formula typically assesses text only at the level of individual words and sentences, in a purely mechanical way. They measure certain attributes of words and sentences in isolation, ignoring other important attributes at the sentence level, including how writer has connected sentences into paragraphs. By applying scientific and mathematical principles, the readability principles aim to present an objective analysis about the readability of a particular text. Some of the commonly used readability formulas are: Dale-Challa readability formula (1948), PSK Readability Formula (1958), Gunning's FOG index (1964), FK Grade Level Formula (1975), and McAlpine EFLAW formula (2006). Word processor's tool analyzes the text supplied by a user and calculates the number of characters in the sentences, words and syllables and finds reading level and grade level of the text by applying any of the readability formulas used by it. Readability formulas have many advantages, but these are being often criticized as *over-simplification and a critique of creative writing'. Indeed most great literary works may fail to pass the readability tests, though they are of very high quality. These formulas are more relevant for textbooks and subject books. While efforts should be made to have readability formulas which can give more accurate results, the authors should also be more alert to take prepublication readability tests of their creations so that we can have more readable books.