The IRS states that they issue most refunds in less than 21 calendar days from the date the return was accepted by the IRS. This is a target only and not a guarantee.
It can take anywhere from a few hours to 3 weeks for the IRS to officially accept your return and then your information should show in the Refund tool within 24 hours of acceptance.
You can check the status of your refund by going to the IRS Refunds page. You can click on the Check My Refund Status link or download the IRS2Go app for your mobile device. Wait at least 24 hours after your return has been accepted