The Fairfax County Board of Supervisors was told last night that revised revenue estimates plus a surplus in its current budget will permit cutting the real estate tax rate by seven cents and that with cuts in the proposed budget a ten-cent cut may be possible.

The supervisors are expected to set the new tax rate early next week.

Even with a 10-cent cut in the present tax rate of $1.64 per $100 of assessed valuation, the average home owner would pay higher taxes because of rising assessments.

The owner of a home assessed at $60,000 last year paid $984 in taxes. If that home's assessment has risen the average of 8 percent, to $64,800, the owner could expect to pay about $14 more this year with a dime's reduction in the tax rate.

The addition of almost $8.9 million to the revenue estimate for the fiscal year that will start July 1 plus various fiscal adjustments and a $1.5 million surplus from the current fiscal year would permit most of the tax cut, according to a report prepared by Acting County Executive J. Hamilton Lambert.

An additional cut of $1.4 million in the proposed $628.1 million budget would permit the rest.

County Board Chairman John F. Herrity has said he expects the board to attempt to cut the tax rate between 5 and 10 cents.