How many 80 lb bags of concrete are in a cubic yard?

45 bags. An 80 lb bag yields about 0.6 cubic feet, and a cubic yard is 27 cubic feet. For 60 lb bags it's 60 bags per yard.

How thick should a concrete driveway be in Minnesota?

Five inches is the practical minimum for a residential driveway here, and six inches if you park a truck, RV or trailer on it. Combined with 6 inches of compacted Class 5 base, that thickness is what survives freeze-thaw.

How deep do footings need to be in the Twin Cities?

Footings supporting a structure generally have to sit below the frost line, which is typically 42 inches or deeper in the metro. Confirm the exact depth with your city's building department — it varies and it's checked at inspection.

Do I need a permit to pour a slab?

Flatwork like a patio at grade often doesn't need one, but driveways, aprons touching the public right-of-way, and anything structural usually do. Cities also regulate impervious surface coverage. Check before you order the truck.

Concrete Calculator — Yards, Bags & Cost (Minnesota)

Slab area	400 sq ft
Concrete volume	4.94 cubic yards
Order with 10% wasteReady-mix plants sell in 1/4-yard increments — round up.	5.43 cubic yards
60 lb bags (if bagging it)	297 bags
80 lb bags (if bagging it)	223 bags
Class 5 base, 6" compactedMinnesota freeze-thaw makes the base as important as the concrete.	7.4 cubic yards

Why Minnesota concrete costs more than the national average

Frost depth is the whole story. Metro code generally puts footings for anything supporting a structure below the frost line — commonly 42 inches or more in the Twin Cities — and flatwork needs a properly compacted granular base so the freeze-thaw cycle doesn't heave it. A slab poured on undisturbed clay with no base will look fine in October and crack by April.

The other cost driver is the pour window. Ready-mix in a Minnesota winter means blankets, heated water, accelerators, or waiting until spring. Scheduling in May through September is meaningfully cheaper than trying to force a November pour.

How to use the numbers

The cubic-yard figure is your true volume. The 10% waste line is what you actually order — spillage, uneven subgrade and over-excavated edges eat concrete every single pour. Running short mid-pour creates a cold joint, which is a permanent weak line in the slab.

Bag counts are shown for small pours only. Past roughly one cubic yard (about 45 to 60 bags), mixing by hand stops making sense and a short-load truck is cheaper once you value your Saturday.

Common questions

How many 80 lb bags of concrete are in a cubic yard?: 45 bags. An 80 lb bag yields about 0.6 cubic feet, and a cubic yard is 27 cubic feet. For 60 lb bags it's 60 bags per yard.
How thick should a concrete driveway be in Minnesota?: Five inches is the practical minimum for a residential driveway here, and six inches if you park a truck, RV or trailer on it. Combined with 6 inches of compacted Class 5 base, that thickness is what survives freeze-thaw.
How deep do footings need to be in the Twin Cities?: Footings supporting a structure generally have to sit below the frost line, which is typically 42 inches or deeper in the metro. Confirm the exact depth with your city's building department — it varies and it's checked at inspection.
Do I need a permit to pour a slab?: Flatwork like a patio at grade often doesn't need one, but driveways, aprons touching the public right-of-way, and anything structural usually do. Cities also regulate impervious surface coverage. Check before you order the truck.

Concrete Calculator