A dissertation is a long task. The time it takes to proofread a dissertation takes time and will depend on a variety-a number of factors including word count, type and complexity of the topic, etc. In general, a dissertation has a word count between 20,000 and 70,000. For a 20,000-word dissertation, it usually takes 2-3 days as proofreading for an average topic. However, if the same dissertation has a super complicated topic, then it could take 1-2 weeks to proofread. Therefore, if you are in a hurry and need your dissertation proofread as soon as possible, the best option is to seek a professional dissertation proofreading service. They provide quick turnaround time and high-quality service.