Concrete Yard Calculator
Concrete is sold by the cubic yard in North America and by the cubic metre almost everywhere else. Enter your dimensions to get both — and see when your yardage is large enough to batch on site.
Floors, pads, patios, driveways — flat rectangular pours.
How to calculate cubic yards of concrete
The formula
A cubic yard is a cube 3 ft on each side — 27 cubic feet. To get yardage, find the volume in cubic feet, then divide by 27. The calculator also shows cubic metres because 1 cubic yard = 0.765 m³.
- Cubic yards = (length ft × width ft × thickness ft) ÷ 27.
- 1 cubic yard = 27 ft³ = 0.765 m³.
- 1 cubic metre = 1.308 cubic yards.
Worked example
A 40 ft × 10 ft footing trench, 12 inches deep:
- Volume = 40 × 10 × 1 = 400 ft³.
- Cubic yards = 400 ÷ 27 = 14.8 yd³.
- That's 11.3 m³ — large enough to consider on-site batching.
About 14.8 cubic yards (11.3 m³) before waste.
Sizing, thickness & waste
Yardage rules of thumb
- 1 yd³ ≈ a 9 ft × 9 ft slab at 4 inches thick.
- Most mixer trucks carry 8–10 yd³ per load.
- Short loads (under ~3 yd³) often carry a delivery surcharge.
When yardage gets big
Above about 13 yd³ (10 m³) on a job — especially if it repeats or the site is remote — batching on site usually beats per-load delivery on both cost and schedule.
What produces this much concrete?
Match your yardage to the right production method:
Small pour — mix on site
Under ~0.5 m³ (≈0.65 yd³) you can mix on site from bags. A portable mixer saves time over hand-mixing once you pass a few bags.
Medium pour — small mixer or ready-mix
From ~0.5–2 m³, a small or self-loading mixer keeps you independent of delivery schedules; otherwise order ready-mix.
Large pour — self-loading mixer or delivery
At 2–10 m³, compare ready-mix delivery against a self-loading mixer or mixer truck if you pour regularly.
On-site batching becomes economical
Above ~10 m³, repeated or remote pours usually cost less with on-site batching than per-load delivery. A mobile or compact plant sets up fast.
Continuous production — dedicated plant
Beyond ~50 m³ per job, a stationary or ready-mix plant delivers the throughput and consistency large projects need.
Frequently asked questions
How do I calculate yards of concrete?
Multiply length × width × thickness in feet to get cubic feet, then divide by 27 to get cubic yards. Enter your dimensions above and the calculator returns both cubic yards and cubic metres.
How do you calculate concrete yardage?
Yardage is just cubic yards. Find the volume in cubic feet and divide by 27 — for example 162 ft³ ÷ 27 = 6 cubic yards. The calculator above does the division for you.
How do you calculate cubic yards of concrete?
Take length × width × thickness (all in feet) for cubic feet, then divide by 27. A 20 ft × 18 ft slab at 6 inches = 20 × 18 × 0.5 = 180 ft³ = 6.7 cubic yards.
How many cubic feet are in one cubic yard of concrete?
There are 27 cubic feet in one cubic yard. One cubic yard also equals 0.765 cubic metres, and one cubic metre equals 1.308 cubic yards.
How do you calculate square yards of concrete?
Square yards measure area, not volume: divide the area in square feet by 9 (a square yard is 3 ft × 3 ft). Concrete is ordered by the cubic yard, so multiply the area by thickness and divide by 27 for what to order.
How many yards of concrete do I need for a slab?
Multiply the slab area by its thickness in feet, then divide by 27. A 24 ft × 24 ft slab at 4 inches needs about 7.1 cubic yards before waste.
What is the formula for concrete yards?
Cubic yards = (length ft × width ft × thickness ft) ÷ 27. For round columns, replace length × width with π × (diameter ÷ 2)².
How much extra concrete should I order for waste?
Add 5–10% to your calculated volume to cover spillage, uneven subgrade, and over-excavation. For small or irregular pours, 10% is safer because running short mid-pour creates a cold joint.