Road Base Calculator
Road Base Calculator: How Much Road Base Do You Need?
Road base is the unsung foundation of every driveway, parking lot, patio, and paved surface. Get the quantity wrong and you’re either making a second delivery run or wasting money on material you didn’t need. This guide explains exactly how to calculate road base in tons, cubic yards, and square feet — with worked examples, coverage tables, and pricing for 2026.
What Is Road Base?
Road base is a layer of compacted crushed rock or gravel placed on the subgrade of a road, driveway, parking area, or paved surface. Its main function is to distribute vehicle loads, provide structural support to the pavement above, and dissipate stress to the layers below — preventing cracking and deformation over time.
Road base materials go by many names depending on the region and specification:
- 3/4-inch minus (most common residential grade)
- Class 2 road base (California DOT standard, crushed aggregate)
- Aggregate base course (ABC) or dense-grade aggregate (DGA)
- Crusher run, road rock, or asphalt base (AB)
All of these are angular, crushed stone products — usually granite or limestone — that compact tightly to form a stable foundation.
How to Calculate Road Base: Step by Step
Use these steps to find the volume and tonnage of road base you need:
Step 1 — Measure your area in feet
Area = Length × Width
Step 2 — Convert depth to feet
Depth (ft) = Depth (inches) ÷ 12
Step 3 — Calculate volume in cubic feet
Volume (cu ft) = Area × Depth (ft)
Step 4 — Convert to cubic yards
Cubic Yards = Cubic Feet ÷ 27
Step 5 — Convert to tons
Tons = Cubic Yards × 1.35 (standard road base density)
Step 6 — Add 10–15% for compaction and waste
Worked Example: Driveway Road Base
Driveway: 60 ft long × 12 ft wide, 6 inches of road base depth.
- Area: 60 × 12 = 720 sq ft
- Depth: 6 ÷ 12 = 0.5 ft
- Volume: 720 × 0.5 = 360 cu ft
- Cubic yards: 360 ÷ 27 = 13.33 cu yd
- Tons: 13.33 × 1.35 = 18.0 tons
- With 12% compaction buffer: ~20.2 tons to order
Our road base calculator runs this formula automatically — enter your dimensions in feet, yards, or metres and it outputs both cubic yards and tons instantly.
Road Base Calculator: Coverage Tables
Tons of Road Base Per Square Foot
Road base gravel costs $18 to $31 per ton or $25 to $62 per cubic yard, with coverage of $0.59 to $1.50 per square foot at standard depths.
| Depth | Tons Per 100 sq ft | Tons Per 500 sq ft | Tons Per 1,000 sq ft |
|---|---|---|---|
| 2 inches | 1.25 tons | 6.25 tons | 12.5 tons |
| 3 inches | 1.88 tons | 9.38 tons | 18.75 tons |
| 4 inches | 2.50 tons | 12.5 tons | 25.0 tons |
| 6 inches | 3.75 tons | 18.75 tons | 37.5 tons |
| 8 inches | 5.00 tons | 25.0 tons | 50.0 tons |
Based on compacted road base at 1.35 tons per cubic yard.
How Much Does 1 Ton of Road Base Cover?
| Depth | Coverage Per Ton |
|---|---|
| 2 inches | ~80 sq ft |
| 3 inches | ~53 sq ft |
| 4 inches | ~40 sq ft |
| 6 inches | ~27 sq ft |
Road Base Calculator in Cubic Yards
Many suppliers quote by the cubic yard rather than by the ton. Here’s the same coverage data expressed in yards:
| Area | 4 inches deep | 6 inches deep | 8 inches deep |
|---|---|---|---|
| 100 sq ft | 1.23 cu yd | 1.85 cu yd | 2.47 cu yd |
| 500 sq ft | 6.17 cu yd | 9.26 cu yd | 12.35 cu yd |
| 1,000 sq ft | 12.35 cu yd | 18.52 cu yd | 24.69 cu yd |
| 2,000 sq ft | 24.69 cu yd | 37.04 cu yd | 49.38 cu yd |
How much does 1 cubic yard of road base weigh? Standard compacted road base weighs approximately 2,700–2,800 lbs per cubic yard (1.35–1.40 short tons). One cubic yard of crushed stone typically equals 1.5 tons, while gravel and river rock average 1.4 tons per cubic yard.
How Thick Should Road Base Be?
Road base is generally laid to a total depth of 100 to 150 mm (4 to 6 inches) for standard residential applications. Always check your regional regulations and building codes.
Here are practical depth guidelines by project type:
| Project Type | Recommended Depth | Notes |
|---|---|---|
| Foot path / walkway | 3–4 inches | Light foot traffic only |
| Patio base | 4–6 inches | Standard residential patio |
| Residential driveway | 4–6 inches | Single vehicles, standard use |
| Heavy vehicle driveway | 6–8 inches | Trucks, RVs, heavy SUVs |
| Parking lot (light) | 6 inches | Passenger vehicles |
| Parking lot (heavy) | 8–12 inches | Commercial, delivery trucks |
| Road sub-base | 8–12 inches | Public or commercial road |
| Pavers base | 4–6 inches | Before sand and paver installation |
Road Base Calculator for Pavers
When using road base as the foundation layer beneath pavers, the calculation is the same formula — but you’ll need to account for both the road base layer and the bedding sand layer separately.
Typical paver base stack:
- Road base (compacted): 4–6 inches
- Bedding sand: 1 inch
- Pavers: varies
For a 200 sq ft patio with 5 inches of road base:
200 × (5/12) = 83.3 cu ft ÷ 27 = 3.09 cu yd × 1.35 = 4.17 tons of road base
Add 10% = order 4.6 tons (5 tons for a safe round-up).
Class 2 Road Base vs. 3/4-Inch Road Base: What’s the Difference?
| Type | Gradation | Best For | Compaction |
|---|---|---|---|
| 3/4-inch minus | 3/4″ max, includes fines | Driveways, general base | Excellent — fines fill voids |
| Class 2 road base | 3/4″ max crushed aggregate | Driveways, roads, pads | Excellent — California DOT spec |
| Class 3 / AB | 1″ max, coarser | Sub-base for roads | Good |
| Crusher run / DGA | Mixed sizes with stone dust | Compacted base for heavy loads | Excellent |
| 3/4″ clean (washed) | 3/4″ no fines | Drainage layers, French drains | Poor — does not bind |
For most driveways and paver bases, 3/4-inch minus and Class 2 road base are functionally identical and interchangeable. Class 2 is the California DOT designation for the same material.
Road Base Cost Per Ton and Cubic Yard (2026)
Road base gravel costs $18 to $31 per ton, $25 to $62 per cubic yard, or $0.59 to $1.50 per square foot.
| Supply Method | Price Range |
|---|---|
| Pick-up at quarry | $18–$31 per ton |
| Bulk delivery (local, <10 miles) | $25–$50 per ton (delivered) |
| Per cubic yard (bulk) | $25–$62 per cubic yard |
| Full truck load (15–20 tons) | $400–$900 delivered |
Buying in bulk reduces per-ton cost by 10–20%. Ordering 10 tons instead of 3 tons might reduce your per-ton cost by $15 to $25.
Is Road Base Cheaper Than Gravel?
Yes — road base is consistently one of the least expensive aggregate materials available. Plain pea gravel or limestone costs $28 to $45 per ton, while road base costs $18 to $30 per ton. River rock and decorative gravels run $50–$130+ per ton.
Road base is cheaper because it’s a functional material — crushed aggregate with fines — rather than a decorative product. The fines (dust and small particles) that make road base excellent for compaction are the same reason it doesn’t look attractive for decorative use.
Road Base Calculation Formula
The standard road base volume formula expressed in full:
Volume (cu ft) = Length (ft) × Width (ft) × Depth (ft)
Cubic Yards = Volume (cu ft) ÷ 27
Tons = Cubic Yards × Material Density (tons/cu yd)
Total Order = Tons × (1 + Compaction Factor)
Standard compaction factor: 10% for well-graded road base; 15% for loosely spread material.
For the road base calculator in square feet: enter your area directly and skip the L×W multiplication step — just multiply square footage × depth (in feet) ÷ 27 × 1.35 for tons.
Frequently Asked Questions
How Do I Figure Out How Much Road Base I Need?
Multiply your area (length × width) by the depth in feet, divide by 27 for cubic yards, then multiply by 1.35 for tons. Add 10–15% for compaction. Use our road base calculator at the top of this page to handle the math instantly for any combination of dimensions and units.
How Much Does 1 Ton of Road Base Cover?
At 4-inch depth, 1 ton of road base covers approximately 40 square feet. At 3-inch depth, it covers about 53 square feet. At 2-inch depth, roughly 80 square feet. The formula is: Coverage = (1 ton ÷ 1.35 tons/cu yd) × 27 cu ft/cu yd ÷ (Depth in ft) = sq ft.
How Much Does 1 Cubic Yard of Road Base Weigh?
One cubic yard of crushed stone typically weighs 1.5 tons (about 2,700–3,000 lbs). Standard road base and gravel average 1.35–1.45 tons per cubic yard depending on moisture content and material type.
How Thick Should a Road Base Be?
For residential driveways, 4–6 inches of compacted road base is standard. For paver patios, 4–6 inches. For parking lots with regular vehicle traffic, 6–8 inches. For roads handling heavy or commercial vehicles, 8–12 inches is typical.
Is Road Base Cheaper Than Gravel?
Yes. Road base costs $18 to $31 per ton — significantly less than decorative gravel options like pea gravel ($28–$45/ton) or river rock ($45–$130/ton). For structural and functional applications like driveways and paver bases, road base provides better performance at a lower price than decorative alternatives.
What Is the 4:2:1 Rule for Concrete?
The 4:2:1 rule is a concrete mix ratio: 4 parts coarse aggregate (gravel), 2 parts sand, and 1 part cement by volume. It’s the same as a 1:2:4 mix expressed in reverse order and produces general-purpose concrete at approximately 20–25 MPa (3,000–3,600 psi). This is distinct from road base, which is a compacted aggregate layer placed before any concrete or asphalt surface is poured.