The Fairfax County School board is scheduled to vote tonight on a proposed $289 million budget for the coming school year.

Any additions or cuts in the superintendent's proposed budget are to be decided prior to the vote. The meeting will begin at 8 p.m. at the school administration buildings, 10700 Page Ave., Fairfax.

If a proposed budget is accepted, it will be forwarded to the county Board of Supervisors for their consideration and inclusion in the total county budget for fiscal 1978.

The $289 million total reflects an increase of $828,981 over the published budget because of errors, adjustments and special requests that were left out. Supt. S. John Davis made the adjustments at a budget workshop session Monday night.

The current proposal represents an increase of more than 7.3 per cent above last year's school budget. The largest of the five budgets that make up the total proposal is the school operating budget of $240.6 million, up approximately 6.6 per cent over last year's figure.

According to Davis, although the operating budget will increase by only 6.6 per cent, support required from county finding is projected to increase by at least 14.4 per cent or about $18.7 million.

"The major reason for this increase is due to loss of federal impact aid and failure of state aid to keep pace with inflation," said Davis in a letter to the county Board. Davis said the state may farther reduce school funds next year.

At the workshop, Board members expressed their concern about possible reduction in state aid, possible increases in the utility rates and a possible state change in the required pupil-per-teacher ratio.

"It seems to me that the budget depends on a lot of things that are yet to happen," Board chairman Rodney F. Page told the members.

Some of the possible budget cuts mentioned at the meeting were elimination of dining room aides, part-time clerical workers and media specialists, cutting some kindergarten staff, increasing summer school tuition and elimination of a $10,000 training room.

However, Mary Anne Lecos, who represents the Mason District on the Board, told the group, "You will not be able to get volunteers to help in the dining room and the aides will come out of the instructional program one way or the other." She urged the group to support the dining aides provision.

Frank Alston, an at-large member of the Board, objected to the reduction of the compensatory education kindergarten staff for disadvantaged children. He also suggested that the school board divest itself of some of its plane-tariums.

The superintendent prepared the way for tonight's vote with a series of briefings for community groups and board members that began the first week in January. Public hearings, where board members heard testimony from more than 50 community group representatives and individuals, were held last week.