There are several types of sealant on the market, all of which are sold and applied on a square foot cost basis, which means that every driveway has its own cost. The national average range to sealcoat an asphalt driveway is $355 - $600, with most people paying around $468 for an asphalt-based sealer on a flat 20 x 20-foot flat driveway in fair condition.
Asphalt Sealing Costs
Any fissures, cracks, or chips must be smoothed over or filled in before you can apply any sealant. The average cost to repair asphalt paving is $1 to $4 per square foot. This makes expensive repairs cost as much as $5,500 and low-end as affordable as $300, with the national average at $2,000, which lands in the typical cost range of $900 to $3,000.
Before sealing a surface, you must also have it free from any oil, dirt, or debris. You can most likely clean the driveway yourself, but if it's terribly dirty, oily or filled with debris, it might require a professional power washing to get it clean enough to take the sealant. The average cost of powerwashing is $280. This is a factor that should add to your costs to present a realistic expectation of what to save for the job.