The vote in the referendum started on Saturday. About 61 million Egyptian citizens were able to vote.
In accordance with a law, Egypt's National Elections Commission should declare results of the voting until 27 April. The amendments will enter into force immediately after its public approval is announced.
The referendum was held after the Egyptian parliament passed by a bill on changes to the constitution. The amendments envisage increasing the president's term from four years to six, creating an upper house of parliament, which is currently unicameral, and granting the president the right to appoint vice presidents.
According to the existing constitution of Egypt adopted in 2014, either the president or a group of lawmakers representing at least one fifth of the parliament can propose changes to the country's basic law. Any changes to the constitution of Egypt must be approved in a national referendum after two-thirds of the legislature's lawmakers vote for it.