Pavement Calculator

About the Pavement Calculator

On a paving job, asphalt arrives one truckload at a time, and the crew needs to know how far each load will go. Too thin and the pavement fails early; too thick and the job runs out of asphalt before the end of the road. Paving crews and inspectors manage this with the spread rate, the weight of asphalt laid on each square yard, and the yield, how many square yards each ton covers.

This pavement calculator works from a quantity of asphalt, such as a truckload, and tells you how much area and length it will pave at your width and compacted thickness. It also gives the target spread rate and the yield per ton, which are the numbers a crew checks as the paver moves.

How to Use the Pavement Calculator

Enter the asphalt available in tons, for example the weight on a truck ticket.

Enter the paving width in feet and the compacted thickness in inches.

The Formulas

  spread rate (lb/yd²) = thickness × 110
  area (yd²)           = tons × 2,000 ÷ spread rate
  area (ft²)           = square yards × 9
  length (ft)          = square feet ÷ width
  yield per ton        = 2,000 ÷ spread rate

Step-by-Step Example

A 20-ton truckload, paved 12 ft wide and 2 inches thick.

  spread rate   2 × 110 = 220 lb/yd²
  area          20 × 2,000 ÷ 220 = 182 yd² = 1,636 ft²
  length        1,636 ÷ 12 = 136 ft
  yield         2,000 ÷ 220 = 9.09 yd² per ton

The 110 Pounds Rule

Compacted dense-graded hot-mix asphalt weighs about 145 pounds per cubic foot. A square yard one inch thick holds 9 × 1 ÷ 12 = 0.75 cubic feet, which weighs about 109 pounds. Rounded to 110, this gives the simple rule crews use: 110 pounds per square yard per inch. A 1½-inch surface course needs about 165 pounds per square yard, and a 3-inch layer about 330.

Checking Yield on the Job

As each truck unloads, the crew records its weight from the ticket and measures the length paved. Dividing the weight by the area gives the actual spread rate. If it is running high, the mat is too thick or the base has low spots soaking up mix; if it is low, the mat may be too thin. The paver operator adjusts the screed to bring it back on target. Tracking yield load by load is how contractors make sure the asphalt ordered matches the job.

Planning Truck Deliveries

Knowing how far one load paves helps schedule trucks. If each load paves 136 feet and the paver moves at a steady pace, you can work out how often a truck must arrive to keep paving without stopping. Stopping the paver leaves a bump and a weaker joint, so steady deliveries matter as much as total tonnage.

Base Condition

The calculation assumes the asphalt is laid on a smooth, true base at a uniform thickness. Over an old, rutted road surface, the first layer, called a leveling or scratch course, fills dips and uses far more asphalt in some places than others. Milling the old surface first gives a more even base and more predictable yield.

Converting Thickness and Yield

The spread rate scales directly with thickness, so it is easy to compare options. At 1 inch, a ton covers about 18 square yards; at 1½ inches about 12; at 2 inches about 9; at 3 inches about 6. Doubling the thickness halves the area each ton covers, so a thicker pavement needs proportionally more trucks and a larger budget. That is why designers choose the thinnest pavement that will carry the expected traffic over its life.

Patching and Small Jobs

For patches and small areas, the same rule tells you how much asphalt to buy. A pothole patch 3 feet by 2 feet and 2 inches deep is two-thirds of a square yard, needing about 147 pounds of mix, three 50-pound bags of cold patch. Cold patch is compacted with a tamper or by driving over it, and works best in a clean, dry hole with straight sides.

Width and Joints

Paving machines lay a set width, often 8 to 16 feet. Wider areas are paved in lanes side by side, with a longitudinal joint between them. Planning widths to suit the paver reduces the number of joints, which are the weakest points in the pavement. Each lane is calculated with its own width, and the lengths and tonnages added together.

Compaction and Density

The spread rate only gives the right thickness if the mat is rolled to its target density. Loose mix behind the paver is about 20 to 25% thicker than the finished mat, and the rollers bring it down. Under-compacted asphalt is thicker than planned but weaker and more porous, so it ages and cracks sooner.

Understanding Your Result

The headline gives the length of pavement the asphalt will lay.

The area line shows square yards, square feet and the width.

The spread rate line gives the target pounds per square yard.

The yield per ton line shows how far each ton goes.

When Should You Use This Calculator?

Use it to plan how far each truckload will pave.

Use it to check spread rate and yield during a job.

Use it to work out whether the asphalt left will finish a section.

Common Mistakes

Ignoring the base condition. Ruts and dips take extra mix.

Using loose thickness. Spread rate is for the compacted mat.

Stopping the paver between trucks. It leaves bumps and joints.

Assuming every mix weighs the same. Check the job mix figure.