How Much Is a Bag of Concrete? Cost, Yield & 1 Yard

Answer first: a bag of concrete should be compared by cost per cubic foot of mixed yield, not only by shelf price. Common planning yields are about 0.30 ft3 for a 40 lb bag, 0.45 ft3 for a 60 lb bag, and 0.60 ft3 for an 80 lb bag. One cubic yard takes about 90 40-lb bags, 60 60-lb bags, or 45 80-lb bags before waste.

If an 80 lb bag is $6.25 and yields 0.60 ft3, the material-only comparison is about $10.42 per ft3 or $281.25 per yd3 before waste, tax, delivery, tools, base, reinforcement, and labor. Use this example math with your local price because store prices, brands, and delivery rules change.

For the 80 lb shortcut, see how much concrete an 80 lb bag makes.

Use the Concrete Bag Calculator when you want an exact bag count from project dimensions, waste factor, and bag price.

If you are comparing store prices, do not compare bag weight alone. Compare the price against the mixed yield. A cheaper 40 lb bag can still cost more per cubic foot than a larger bag, while an 80 lb bag may be awkward to lift or mix for some DIY jobs.

Bag price decision in one screen

Use this screen before trusting the cheapest shelf tag. It separates the material price from the buying risk that often decides the job.

Official product yields can change by product and region. Confirm the current bag label or product calculator before purchase: QUIKRETE calculator, Sakrete concrete calculators, and NRMCA CIP guidance. Concrete Estimator Hub is independent and is not affiliated with these manufacturers, retailers, or suppliers.

Quick answer by bag size

Use the printed yield on the actual product first. If you only need a planning number, these are common estimates:

With 10% waste, one cubic yard is about 99 40 lb bags, 80 50 lb bags, 66 60 lb bags, or 50 80 lb bags. At that scale, compare ready-mix delivery before buying pallets of bagged concrete.

Concrete bag yield by size

Always check the yield printed on the product bag. These values are common planning estimates:

One cubic yard equals 27 cubic feet, so the bags-per-yard number is:

bags per yard = 27 / bag yield cubic feet

For a deeper conversion table, see the Concrete Bags per Yard Guide. For the exact 40 lb one-yard shortcut, see How Many 40 lb Bags of Concrete Are in a Yard?. For the exact 60 lb one-yard shortcut, see How Many 60 lb Bags of Concrete Are in a Yard?. For the exact 80 lb one-yard shortcut, see How Many 80 lb Bags of Concrete Are in a Yard?.

Quick bag cost comparison

Bag prices change by store, region, brand, and delivery method. Use your local price, then divide by yield:

cost per cubic foot = bag price / bag yield cubic feet
implied bagged cost per yard = cost per cubic foot x 27

Example only:

This table does not mean every 80 lb bag is automatically the best buy. It shows the math you should run on the actual shelf price. If a store has a sale on 60 lb bags, or if delivery/pickup limits make 80 lb bags difficult, the best choice can change.

For a full ready-mix comparison, use the Ready-Mix vs Bags Cost Guide or enter your local numbers in the Ready-Mix vs Bags Calculator.

Best calculator inputs for bag shopping

When you compare bag prices, enter the product details exactly as sold. A generic bag size is useful for planning, but store decisions should use the actual bag you can buy today.

If two bags are close on price per cubic foot, choose the one your crew can lift, stage, and mix safely. The mathematically cheapest bag is not always the best project choice.

Real store cost checklist

The shelf price is only one part of the buying decision. Heavy bagged concrete often has costs that do not show up in the first calculation.

If your order is close to a full pallet, check How Many Bags of Concrete Are on a Pallet? before choosing pickup or delivery.

For larger projects, compare the bagged material total with the delivered ready-mix total from Concrete Cost per Yard.

Shelf price red flags

Use these checks when one bag looks much cheaper than another.

For a few bags, shelf price is usually enough. For dozens of bags, cost per cubic foot, delivery, returns, and mixing pace should all be visible.

How far does one bag of concrete go?

Coverage depends on thickness. A bag covers more area at 2 in thick than at 4 in thick.

The formula is:

coverage square feet = bag yield ft3 / thickness ft

For a 4 in slab, thickness is 4 / 12 = 0.333 ft. An 80 lb bag at 0.60 ft3 covers about:

0.60 / 0.333 = 1.8 ft2

Coverage by common thickness

Use this quick check when a product page gives yield but not your exact slab thickness.

Coverage drops quickly as thickness increases. If the base is uneven or the forms are deeper than planned, buy enough waste margin before rounding.

How to calculate how many bags you need

First calculate project volume:

cubic feet = length ft x width ft x thickness ft

Then divide by bag yield:

bags needed = cubic feet / bag yield cubic feet

Add waste before rounding up to whole bags:

bags to buy = round up(bags needed x (1 + waste percentage))

A 5% to 10% waste factor is common for simple estimates. Irregular forms, uneven base, spills, or measurement uncertainty may need more.

Example: 4 ft by 4 ft pad

Assume:

• Length: 4 ft
• Width: 4 ft
• Thickness: 4 in
• Bag size: 80 lb
• Bag yield: 0.60 ft3
• Waste: 10%

Volume:

4 x 4 x 4 / 12 = 5.33 ft3

Bag count:

5.33 / 0.60 = 8.89 bags
8.89 x 1.10 = 9.78 bags
round up to 10 bags

Planning estimate: buy 10 bags of 80 lb concrete mix.

Example: 10 ft by 10 ft slab

Assume a 10 ft by 10 ft slab at 4 in thick:

10 x 10 x 4 / 12 = 33.33 ft3

Using 80 lb bags at 0.60 ft3:

33.33 / 0.60 = 55.55 bags
55.55 x 1.10 waste = 61.11 bags
round up to 62 bags

At this size, compare bagged concrete with delivery using the Ready-Mix vs Bags Calculator. The material cost may look close, but mixing dozens of bags can be slow and physically demanding.

How to estimate bag cost

Bagged concrete cost is simple once you know the bag count:

bagged concrete cost = bags to buy x price per bag

If the example above needs 62 bags and each bag costs $5.50:

62 x $5.50 = $341.00

That is a material-only number. It does not include tools, mixer rental, base material, reinforcement, delivery, tax, labor, or cleanup.

For a more realistic buying estimate, price the project in layers:

Do not compare bag material cost with a contractor's installed quote. A contractor quote may include labor, forming, base prep, reinforcement, finishing, cleanup, overhead, and warranty risk.

For local ready-mix pricing, short-load fees, and delivery charges, see the Concrete Cost per Yard Guide and the Concrete Cost Calculator.

Project price worksheet

Use this worksheet before you compare bags with a ready-mix quote.

This keeps a cheap bag price from being compared against a complete delivered ready-mix number. Both sides should include the costs that actually apply to your job.

Bag type changes the answer

Concrete mix, mortar mix, sand mix, fast-setting post mix, and topping mix are not interchangeable. Even if bags weigh the same, the yield, intended thickness, strength, and working time can differ.

If the project is permitted, structural, or load-bearing, confirm the required mix, reinforcement, thickness, and inspection steps before buying.

Half-yard and one-yard examples

These are common points where bagged concrete starts to feel much larger than the shelf price suggests.

The material math can still favor bags for a small order with high short-load fees, but the handling plan has to be realistic.

When to check ready-mix instead of bags

Bagged concrete is convenient for small pads, posts, repairs, and projects where a truck cannot reach. It becomes less attractive when the bag count is high or the pour needs to be placed quickly.

Use this practical screen:

The cutoff is not only price. A slab must be mixed, placed, screeded, and finished while the concrete is workable. The larger the pour, the more timing matters.

If your project is a common slab size, these guides can help you sanity-check the bag count:

• Concrete Bags for a 4x4 Slab
• Concrete Bags for a 6x6 Slab
• Concrete Bags for an 8x8 Slab
• Concrete Bags for a 10x10 Slab
• How Many Bags of Concrete for 100 Square Feet?

Buying checklist

• Confirm the bag yield printed on the product.
• Compare price per cubic foot, not only price per bag.
• Match the mix type to the project.
• Add waste before rounding up.
• Check store pickup, delivery, and total dry weight.
• Check pallet quantity if the order is close to store delivery scale.
• Include tax, tool rental, and base/reinforcement materials.
• Compare total bag weight, not only material price.
• Keep bags dry before mixing.
• For dozens of bags, compare ready-mix before buying.

FAQ

How much concrete is in a 40 lb bag?

A 40 lb bag commonly yields about 0.30 cubic feet. That is about 90 bags per cubic yard before waste, or about 99 bags with 10% waste.

How much concrete is in an 80 lb bag?

An 80 lb bag commonly yields about 0.60 cubic feet of mixed concrete. That is about 45 bags per cubic yard before waste, or about 50 bags with 10% waste.

How much concrete is in a 60 lb bag?

A 60 lb bag commonly yields about 0.45 cubic feet. That is about 60 bags per cubic yard before waste, or about 66 bags with 10% waste.

How much area does one 80 lb bag cover at 4 inches thick?

At 4 in thick, an 80 lb bag with a 0.60 ft3 yield covers about 1.8 square feet.

Which concrete bag size is usually cheapest?

The cheapest bag size is the one with the lowest cost per cubic foot, not the lowest shelf price. Divide the bag price by the printed yield. A larger bag is often cheaper per cubic foot, but store sales and delivery fees can change the answer.

Is an 80 lb bag always better than a 60 lb bag?

No. An 80 lb bag usually gives more concrete per bag and reduces the total bag count, but it is heavier to lift, carry, and pour into a mixer. A 60 lb bag may be the better choice when handling weight matters more than the absolute lowest material cost.

How much does one cubic yard cost in bags?

Multiply the bags per yard by your local price per bag. For example, one yard is about 45 80 lb bags before waste. At $6.25 per bag, that is $281.25 before waste, tax, delivery, tools, and labor.

How many bags before ready-mix makes sense?

There is no universal cutoff, but once you are in the dozens of bags, compare ready-mix. The decision depends on local bag price, ready-mix price per yard, short-load fees, truck access, mixer rental, labor, and how quickly the pour must be finished.

Should I buy extra bags?

Usually yes. Add a waste factor before rounding up, then consider buying one or two extra bags for small projects where running short would be a problem.

Can I store extra bags for later?

Only if they stay dry and protected. Bagged concrete can harden or lose quality when it absorbs moisture. For important work, do not rely on old or partially hardened bags.

Is fast-setting concrete the same as regular concrete mix?

No. Fast-setting mixes are useful for many post holes and quick repairs, but they have shorter working time and may not be appropriate for slabs or larger continuous pours. Match the product label to the project.

Why does one bag cover less than I expected?

Coverage drops as thickness increases, and uneven base, over-excavation, spills, and form variation use extra material. Use the printed yield, calculate the real thickness, and add waste before rounding up.

Next step

Use the Concrete Bag Calculator to calculate the exact bag count and material cost for your project. If the bag count is high, compare delivery with the Ready-Mix vs Bags Calculator.