How Much Gravel Do I Need? A Calgary Homeowner's Guide
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If you've ever stared at a patch of driveway or a garden bed and thought "I have no idea how much gravel to order" — you're not alone. It's one of the most common questions we get. Order too little and you're making a second trip. Order too much and you've got a pile sitting in your yard for the rest of the season.
Here's exactly how to figure it out.
The Basic Formula
All gravel is sold by the cubic yard. To calculate how many cubic yards you need, you only need three numbers: the length of your area, the width, and the depth of gravel you want.
The formula is:
Length (ft) × Width (ft) × Depth (inches) ÷ 324 = Cubic yards
That's it. The 324 accounts for converting inches to feet and square feet to cubic yards in one step.
A Few Real Examples
Driveway: 40 ft long × 12 ft wide × 4 inches deep = 40 × 12 × 4 ÷ 324 = 5.9 cubic yards. Round up to 6.5 to be safe.
Garden bed: 20 ft long × 8 ft wide × 2 inches deep = 20 × 8 × 2 ÷ 324 = 1 cubic yard.
Parking pad: 20 ft × 20 ft × 6 inches deep = 20 × 20 × 6 ÷ 324 = 7.4 cubic yards.
How Deep Should You Go?
Depth depends on what you're using the gravel for:
- Decorative garden beds and pathways — 2 inches is enough for coverage and weed suppression
- Around trees or shrubs — 3 inches gives better moisture retention
- Driveways and parking pads (top layer) — 3 to 4 inches of decorative rock over a compacted road crush base
- Road crush base layer — 4 to 6 inches for a solid, stable foundation
- New installs with no existing base — 6 inches of road crush before you add any finishing rock
If you're not sure, go deeper rather than shallower. A thin layer of gravel shifts, sinks, and looks patchy within a season.
Don't Forget the 10% Buffer
Always add 10 to 15% to your final number. Gravel compacts slightly when it settles, and you'll lose a bit to edges, corners, and uneven ground. It's much easier to have a small amount left over than to reorder mid-project.
Which Gravel Should You Use?
This depends on the project:
- Road crush — compacts firm and is the go-to base material for driveways, parking pads, and pathways. Not decorative, but essential underneath.
- Decorative rock (Rundle rock, wash rock, pea gravel) — the finishing layer that people actually see. Choose size and colour based on the look you want.
- Pea gravel — smooth and round, great for play areas and garden borders
- Crush and run (road crush + fines) — best for areas that need to drain well but stay stable
If you're building a driveway from scratch, you typically want road crush as your base (4–6 inches) and decorative rock on top (3–4 inches). Both are available for same-day delivery.
Use Our Free Calculator
If math isn't your thing, we built a free material calculator on our website. Plug in your length, width, and depth and it spits out exactly how many cubic yards to order — no formula needed.
Ready to Order?
We deliver gravel, road crush, and decorative rock same-day across Calgary, Airdrie, Chestermere, Cochrane, Okotoks, and Langdon. Give us a call at 403-510-9011 or order online at newstandardbulk.ca.
