The budget includes expenditure of USD 36.5 billion, up 4.5 percent from 2014, and revenue of USD 30.03 billion, down 1.0 percent, the official ONA news agency cited the finance ministry as saying.
The projected deficit will represent 21 percent of public revenue and 8.0 percent of the sultanate's GDP.
Oman is a small producer of crude, at about one million barrels per day.
Current expenditure accounts for the lion's share at 68 per cent of public spending, far ahead of investments (23 per cent), the ministry said.
However, these "would have no impact" on the standard of living or on social services and employment, it added.
The statement said subsidies on consumer goods and social services in the new budget would account for 8.0 percent of public expenditure in 2015.