The Emma mattress takes up to 2-6 hours to fully inflate. Please also note it is not entirely uncommon for the mattress to not inflate to its full size immediately. Although it is rare what can sometimes happen is that the mattresses are vacuum packed slightly tighter which just leads to a little more time for the full inflation to take place. Although they should reach 90%-95% of the desired depth within 48 hours, it may take an extra couple of days for them to reach the optimal height. If this is not the case, please reach out to our Customer Service team via the ChatBot function in right bottom of the page.