How many 80-lb bags of concrete do I need for a 10x10 slab?

At a standard 4-inch thickness, a 10x10 ft slab is 33.3 cubic feet, which takes 56 bags of standard 80-lb mix (33.3 / 0.60 cu ft per bag, rounded up). That's 4,480 lbs total — more than most half-ton trucks are rated to carry in a single load.

What's the real difference between 80-lb and 60-lb bags?

Less than you'd think for coverage. Standard 80-lb bags yield 0.60 cu ft and 60-lb bags yield 0.45 cu ft — both work out to the same 0.0075 cu ft per pound of bag weight. Pick based on what you can physically lift and carry, not coverage efficiency. The Maximizer 80-lb mix is the outlier, yielding 1.0 cu ft per bag because of its lightweight aggregate.

How thick should a concrete slab be?

4 inches is standard for patios, walkways, and shed bases that only see foot traffic. Bump up to 5-6 inches for driveways or any area a vehicle will drive or park on, and go thicker still, often with rebar, for heavy loads like RV pads or equipment pads.

Can my truck carry the concrete for a driveway pour in one trip?

Often not. Driveway slabs are typically 5-6 inches thick over a large footprint, which can easily push total weight past 2 to 3 tons — well beyond a half-ton truck's payload rating. Run the numbers through the calculator above, compare the total weight to your truck's payload sticker, and plan on multiple trips, a trailer, or delivery if the math doesn't fit.

Is Maximizer 80-lb concrete mix worth it over standard mix?

If you're moving and mixing a lot of bags by hand, yes — it yields about 1.0 cu ft per bag versus 0.60 cu ft for standard 80-lb mix, so you need fewer bags for the same volume, which means less lifting and fewer bags to haul. It's a lightweight-aggregate formula, so check the product's strength rating against your project's load requirements before using it under a driveway.

Concrete Slab Calculator

Punch in the length, width, and thickness of your slab in the calculator above and you'll get an instant bag count, total weight, and truckload estimate. This page walks through the math behind those numbers so you can double-check them, adjust for a different bag size, or figure out mid-project whether you grabbed enough concrete.

The same numbers that tell you how many bags to buy also tell you something else: whether this is a load your truck can handle in one trip, or a job that needs a delivery. A small walkway is a Saturday errand. A driveway slab can weigh more than your truck's entire payload rating — and that's worth knowing before you load up.

Length (ft)Width (ft)Thickness (in)

Common thickness:

MaterialYour truck

You need

56 bags of Concrete mix (80-lb bag)

Area covered: 100 sq ft
Volume: 33.3 cu ft
Total weight: 4,480 lbs
Bag weight: 80 lbs each

That's 3 trips in a Ford F-150 (1,525 lb payload, ~1,493 lbs per trip).

This load exceeds what the F-150 can carry safely in one trip. Split it into 3 trips, or have it delivered.

Order about 10% extra to allow for compaction, settling, and spillage. See Concrete mix (80-lb bag) weight details or run a full payload check.

The formula behind the calculator

Concrete volume is calculated in cubic feet, then converted to bags based on how much each bag yields once mixed. The formula is:

cubic feet = length (ft) x width (ft) x (thickness in inches / 12)

Thickness is almost always specified in inches, so dividing by 12 converts it to feet, keeping all three dimensions in the same unit. Once you have total cubic feet, divide by the yield of whatever bag you're using:

bags needed = cubic feet / yield per bag (cu ft)

Always round up — concrete you can't place is nothing compared to concrete you're short on halfway through a pour.

Picking the right slab thickness

Thickness drives volume more than most people expect, since it's the multiplier on your entire square footage. As a starting point:

Going thicker than needed wastes concrete and money; going thinner than needed risks cracking under load. When in doubt for anything vehicles will drive on, size up.

4 inches — patios, walkways, sheds, and other foot-traffic-only areas
5-6 inches — driveways, parking pads, or anywhere a vehicle will sit or drive
7+ inches (often with reinforcement) — RV pads, dumpster pads, or other heavy equipment loads

Bag sizes and how much each one yields

Bag yield tells you how much cured concrete volume you get out of one bag. Standard mixes scale predictably with bag weight, but one product breaks that pattern:

80-lb bag (80-lb concrete mix) — 0.60 cu ft
60-lb bag (60-lb bags) — 0.45 cu ft
40-lb bag — 0.30 cu ft
Maximizer 80-lb (Maximizer mix) — 1.0 cu ft, thanks to a lightweight aggregate blend that yields nearly double a standard 80-lb bag for the same bag weight, meaning fewer bags to carry and lift for the same volume of concrete
1 cubic yard = 27 cu ft, which works out to roughly 45 standard 80-lb bags

Worked example: a 10x10 patio slab

Take a 10 ft x 10 ft patio poured at the standard 4-inch thickness for foot traffic:

cubic feet = 10 x 10 x (4 / 12) = 100 x 0.333 = 33.3 cu ft

Using standard 80-lb bags at 0.60 cu ft each: 33.3 / 0.60 = 55.5, rounded up to 56 bags.

At 80 lbs per bag, that's 56 x 80 = 4,480 lbs of concrete. That's more than the rated payload of most half-ton pickups, which typically fall somewhere between 1,500 and 2,200 lbs depending on trim and configuration. A slab that size isn't a one-load job in a typical truck — it means multiple trips, a trailer, or having the concrete delivered. Loading a bed past its payload rating isn't just a numbers problem either; see overloading risks for what happens to handling, brakes, and suspension when a truck carries more than it's built for.

When bags stop making sense

Bagged concrete works well for small pours, but it has a practical ceiling. Once a job approaches roughly 1 cubic yard — about 45 or more standard 80-lb bags — ready-mix delivery is usually cheaper, faster, and produces a stronger result. Mixing and placing dozens of bags by hand takes real time, and each batch that sets before the next goes in creates a cold joint, a weak seam where the pour didn't bond into one continuous slab. A ready-mix truck pours the whole slab at once, avoiding that problem entirely.

Tips for a slab that holds up

A few habits separate a slab that lasts decades from one that cracks in year two:

Order about 10% extra material to cover spillage, uneven subgrade, and measurement rounding
Use rebar or wire mesh reinforcement for driveways or any slab that will carry vehicle weight
Compact a gravel base under the slab before pouring — see the paver base calculator for how much base material a given footprint needs
Only mix as much concrete as you can place and finish before it starts to set
Store bags off the ground and sealed against moisture — a damp bag can partially cure inside the packaging and ruin its yield

Frequently Asked Questions

How many 80-lb bags of concrete do I need for a 10x10 slab?: At a standard 4-inch thickness, a 10x10 ft slab is 33.3 cubic feet, which takes 56 bags of standard 80-lb mix (33.3 / 0.60 cu ft per bag, rounded up). That's 4,480 lbs total — more than most half-ton trucks are rated to carry in a single load.
What's the real difference between 80-lb and 60-lb bags?: Less than you'd think for coverage. Standard 80-lb bags yield 0.60 cu ft and 60-lb bags yield 0.45 cu ft — both work out to the same 0.0075 cu ft per pound of bag weight. Pick based on what you can physically lift and carry, not coverage efficiency. The Maximizer 80-lb mix is the outlier, yielding 1.0 cu ft per bag because of its lightweight aggregate.
How thick should a concrete slab be?: 4 inches is standard for patios, walkways, and shed bases that only see foot traffic. Bump up to 5-6 inches for driveways or any area a vehicle will drive or park on, and go thicker still, often with rebar, for heavy loads like RV pads or equipment pads.
Can my truck carry the concrete for a driveway pour in one trip?: Often not. Driveway slabs are typically 5-6 inches thick over a large footprint, which can easily push total weight past 2 to 3 tons — well beyond a half-ton truck's payload rating. Run the numbers through the calculator above, compare the total weight to your truck's payload sticker, and plan on multiple trips, a trailer, or delivery if the math doesn't fit.
Is Maximizer 80-lb concrete mix worth it over standard mix?: If you're moving and mixing a lot of bags by hand, yes — it yields about 1.0 cu ft per bag versus 0.60 cu ft for standard 80-lb mix, so you need fewer bags for the same volume, which means less lifting and fewer bags to haul. It's a lightweight-aggregate formula, so check the product's strength rating against your project's load requirements before using it under a driveway.