Asphalt Tonnage Calculation: HL-3, HL-4, and Granular Base

Calculating asphalt tonnage accurately is essential for paving bids. Underestimate and you’ll run short on material mid-pour. Overestimate and you’ll either inflate your bid or order excess material that can’t be returned. This guide covers the full calculation chain — from PDF plan measurement to final tonnage — for HL-3 surface course, HL-4 binder course, and granular base materials commonly specified in Ontario and Canadian projects.

What Is Asphalt Tonnage and Why Does It Matter?

Asphalt tonnage is the weight of hot mix asphalt (HMA) required for a paving project, measured in metric tonnes. Material suppliers price and deliver asphalt by the tonne, so your tonnage estimate directly drives your material cost line item.

The calculation chain is:

1. Measure the paving area (m²) from plans
2. Determine lift thickness (mm) from specifications
3. Calculate compacted volume (m³)
4. Multiply by density (tonnes/m³) to get tonnage
5. Add waste factor (typically 5–10%)

Getting each step right compounds into an accurate bid. A 5% area measurement error plus a density rounding error can easily push your total off by 10% or more.

How Do You Measure Paving Area from PDF Plans?

Paving areas are measured using the polygon tool — the same approach used for concrete sidewalk takeoffs, but applied to parking lots, roadways, and paving sections.

Step 1: Identify Paving Extents

Look for the paving plan or grading plan in your plan set. The paving extents are usually shown with hatching, shading, or boundary lines. Pay attention to:

• New asphalt areas vs. mill-and-overlay sections (different thicknesses)
• Full-depth reconstruction vs. surface course only
• Tapers and transitions where new pavement meets existing

Step 2: Calibrate Scale and Draw Polygons

Calibrate your viewport scale using a known dimension, then trace the paving boundaries with the polygon tool. For parking lots, you’ll often have:

• Large rectangular or L-shaped main areas
• Drive aisles between parking rows
• Entrance throats and transition areas
• Islands and medians as cutouts

Use BidScoper’s cutout tool to subtract islands, medians, catch basin pads, and other non-paved areas from your polygons.

Step 3: Separate Areas by Specification

Different areas may have different asphalt specifications. A typical municipal parking lot might specify:

• Drive aisles: 90 mm HL-3 surface + 60 mm HL-4 binder on 300 mm Granular A
• Parking stalls: 50 mm HL-3 surface + 50 mm HL-4 binder on 200 mm Granular A
• Heavy-duty entrances: 50 mm HL-3 + 60 mm HL-4 + 100 mm HL-8 base on 450 mm Granular A

Label each measurement with the applicable specification so you can group and total them separately.

How Do You Calculate Asphalt Tonnage from Area?

Once you have your measured areas, the tonnage calculation follows this formula:

Tonnage = Area (m²) × Thickness (m) × Density (t/m³) × (1 + Waste Factor)

Density Values for Common Asphalt Mixes

These are standard planning densities per OPSS and Ontario specifications. Always confirm with your supplier’s actual mix design density.

Mix Type	Description	Planning Density (t/m³)
HL-3	Surface course, fine-graded	2.40
HL-4	Binder course, coarse-graded	2.45
HL-8	Heavy-duty base course	2.45
Superpave 12.5	Surface course (Superpave)	2.42
Superpave 19.0	Binder course (Superpave)	2.45
Superpave 25.0	Base course (Superpave)	2.48

Example Calculation: Parking Lot Resurfacing

Given:

• Paving area: 2,500 m² (measured from PDF plans)
• HL-3 surface course: 50 mm compacted thickness
• HL-4 binder course: 60 mm compacted thickness
• Waste factor: 5%

HL-3 Surface:

• Volume = 2,500 m² × 0.050 m = 125 m³
• Tonnage = 125 m³ × 2.40 t/m³ = 300 tonnes
• With waste = 300 × 1.05 = 315 tonnes

HL-4 Binder:

• Volume = 2,500 m² × 0.060 m = 150 m³
• Tonnage = 150 m³ × 2.45 t/m³ = 367.5 tonnes
• With waste = 367.5 × 1.05 = 386 tonnes

Total HMA: 701 tonnes

How Do You Calculate Granular Base Quantities?

Granular base materials (Granular A, Granular B) are typically specified in cubic metres but may also be priced by the tonne depending on your supplier.

Granular Density Values

Material	Compacted Density (t/m³)
Granular A	2.20
Granular B (Type I)	2.10
Granular B (Type II)	1.95
Granular O	1.60

Example: Granular A Base Calculation

Given:

• Paving area: 2,500 m²
• Granular A depth: 300 mm
• Waste/compaction factor: 10% (granular materials have higher waste due to spreading and compaction losses)

Calculation:

• Volume = 2,500 m² × 0.300 m = 750 m³ (compacted)
• With factor = 750 × 1.10 = 825 m³ loose
• Tonnage = 825 × 2.20 = 1,815 tonnes

What Is the Difference Between Compacted and Loose Volume?

This distinction trips up many estimators. The thickness shown on plans is the compacted thickness — the final in-place dimension after rolling. But granular materials are delivered and spread at loose volume, which is greater than compacted volume.

The relationship:

Loose Volume = Compacted Volume × Compaction Factor

Typical compaction factors:

• Granular A: 1.25–1.35 (25–35% swell from compacted to loose)
• Granular B: 1.20–1.30
• Asphalt (HMA): ~1.15 (accounted for in the density value; planning densities are compacted densities)

When using tonnage, the density values already account for compacted state — so you multiply compacted volume by density to get tonnage. The swell factor matters when you’re ordering by volume (m³) instead of weight (tonnes).

How Does BidScoper Handle Asphalt Calculations?

BidScoper’s Asphalt HL-3/HL-4 on Granular A/B assembly template automates the entire calculation chain. When you apply the template to a polygon measurement:

1. Your measured area feeds into the template as the base input
2. Layer thicknesses (HL-3, HL-4, Granular A, Granular B) are preset to OPSS defaults
3. Density values are built into the output formulas
4. Tonnage for each layer is calculated automatically
5. You can override any variable — change the HL-3 thickness from 50 mm to 90 mm for a specific area without affecting other measurements

The template outputs include:

• HL-3 tonnage
• HL-4 tonnage
• Granular A volume (m³) and tonnage
• Granular B volume (m³) and tonnage
• Tack coat area
• Total paving area

What Are Common Asphalt Tonnage Mistakes?

These errors appear frequently in paving bids:

• Using the wrong density — HL-3 and HL-4 have different densities. Don’t use a generic “2.4” for everything
• Forgetting the waste factor — 5% for asphalt, 10% for granular is a reasonable starting point
• Confusing compacted and loose volumes — plan dimensions are compacted; delivery volumes are loose
• Not separating areas by specification — a parking lot may have three or four different section designs
• Ignoring tapers and transitions — mill-and-overlay transitions add irregular volumes
• Rounding early — carry precision through the calculation chain, round only the final tonnage
• Missing curb and gutter asphalt — some curb details include an asphalt fillet or wedge

What About Asphalt Removal and Milling?

For rehabilitation projects, you also need to estimate removal quantities:

Milling volume = Area (m²) × Mill Depth (m)

Milled asphalt (RAP — Reclaimed Asphalt Pavement) is typically disposed of or recycled at a density of approximately 2.25 t/m³. Your removal tonnage determines trucking and disposal costs.

BidScoper’s Asphalt Removal by Area template calculates removal volume and tonnage from your polygon area and specified mill depth.

Quick Reference: Asphalt Tonnage Calculation Checklist

• Upload PDF plan set and identify paving sheets
• Calibrate viewport scale for each sheet
• Draw polygons around all paving areas
• Subtract islands, medians, and non-paved areas using cutouts
• Label measurements by specification type (drive aisle, parking, heavy-duty)
• Apply the appropriate assembly template (HL-3/HL-4, or Removal)
• Override layer thicknesses per specification section
• Review grouped totals by material type
• Apply waste factors (5% HMA, 10% granular)
• Cross-check tonnage against rough area × rate estimates
• Export CSV for pricing and supplier quotes

Get Accurate Asphalt Quantities in Minutes

Stop wrestling with spreadsheets and manual density calculations. Start a free BidScoper trial and let assembly templates handle the math — so you can focus on winning bids.