Leviticus is 23,399 words. At an average adult reading pace of 300 words a minute that is about 1 hr 18 min, or roughly 58 min if you read quickly and 1 hr 57 min at a more deliberate 200 words a minute.
That count is measured from the complete public-domain text rather than estimated from a page count, so you can compare all the books side by side.