80 lb Concrete Bag Calculator: 0.60 ft3, 1.8 sq ft, 45 Bags

An 80 lb bag of concrete commonly makes about 0.60 cubic feet of mixed concrete. At 4 inches thick, that covers about 1.8 square feet before waste. One cubic yard takes about 45 bags before waste, and most small projects should add a waste factor before rounding up to whole bags.

Use the Concrete Bag Calculator for an exact bag count from project dimensions, thickness, waste factor, and bag price. This guide explains the 80 lb bag math so you can sanity-check the result before you buy.

Answer first

Most-searched answer: an 80 lb concrete bag makes about 0.60 ft3 of mixed concrete, about 1,037 cubic inches, or about 0.022 yd3.
Coverage shortcut: one 80 lb bag covers about 1.8 sq ft at 4 in before waste.
Cubic-yard shortcut: one yard takes about 45 80-lb bags before waste, or about 50 bags with 10% waste.
30 sq ft example: a 30 sq ft pad at 4 in thick needs about 17 80-lb bags before waste, or 19 bags with 10% waste.
Buying decision: once the count approaches a pallet or a full cubic yard, compare store delivery, pickup payload, mixer time, and ready-mix.

Open the Concrete Bag Calculator if you know the project dimensions. Use the answer here as the quick yield check before you buy 80 lb bags.

If you are comparing bagged concrete against delivery, move the final bag count into the Concrete Cost Calculator or the Ready-Mix vs Bags Calculator. For the cross-size yield chart, see the cubic feet of concrete per bag chart.

80 lb bag decision in one screen

The raw yield answer is helpful, but most users really need the buying threshold: when does one bag become a pallet, when does a pallet become a delivery problem, and when does delivery beat dry mix?

Decision	Fast answer	Practical call
One 80 lb bag yield	0.60 ft3	Good for quick repair and slab math.
4 in coverage	1.8 sq ft	Use only as a shortcut, then add waste.
One cubic yard	45 bags before waste	Around a full-yard job, quote ready-mix before checkout.
10% waste yard check	50 bags	This is already a pallet-and-transport question.
Buying breakpoint	25-50 bags	Compare store delivery, pickup payload, mixer time, and ready-mix.

80 lb bag unit conversions in one screen

Bing is showing small but useful searches for 80 lb bag volume in cubic feet, cubic inches, cubic yards, and square feet. Use this table when the query is written in a different unit but the job is still the same 80 lb bag decision.

Query version	Direct answer	Use it for
80 lb bag concrete coverage volume	0.60 ft3	Standard mixed-yield shortcut.
80 lb bag concrete cubic inches	1,037 cu in	`0.60 x 1,728`; useful for odd unit searches.
80 lb bag cubic yards	0.022 yd3	`0.60 / 27`; 45 bags is about 1 yd3.
80 lb concrete bag square feet at 4 in	1.8 sq ft	`0.60 / (4 / 12)` before waste.
30 sq ft at 4 in	17 bags before waste; 19 with 10% waste	Small-pad checkout answer.

So if someone asks how many cubic inches an 80 lb concrete bag covers, the planning answer is about 1,037 cubic inches of mixed concrete. If the question is how many square feet an 80 lb bag covers, include the thickness: at 4 inches, one bag covers about 1.8 square feet before waste.

For a 30 square foot pad at 4 inches thick:

30 x 4 / 12 = 10 ft3
10 / 0.60 = 16.7 bags
round up to 17 bags before waste
17 x 1.10 = 18.7, so buy 19 bags with 10% waste

That is already about 1,520 lb of dry mix before water, so check pickup payload, store delivery, and mixing pace before buying.

Turn the 80 lb result into the next decision

Next question	Best next tool	Why it matters
How many bags do I actually need for my slab or pad?	Concrete Bag Calculator	Converts yield into a project-specific bag count instead of a generic shortcut.
Is this still a store trip or already a delivery job?	Concrete Material Shopping List	Turns bag count into pallets, dry weight, trips, and staging.
Should I skip bags and price ready-mix instead?	Ready-Mix vs Bags Calculator	Once the count approaches a pallet or a cubic yard, delivery can win fast.
Is the budget or quote missing something obvious?	Concrete Quote Reviewer	Helps separate concrete quantity from delivery, fees, base, cleanup, and labor.

The strongest use of this page is not the 0.60 ft3 fact by itself. It is the handoff into a real buying path before you commit to 40, 50, or 60 heavy bags.

Quick answer: how much concrete does an 80 lb bag make?

An 80 lb concrete bag commonly makes about 0.60 ft3 of mixed concrete. That is about 0.022 yd3 per bag, so 45 bags make about one cubic yard before waste.

Question	Planning answer
Volume of one 80 lb bag of concrete	about 0.60 ft3
80 lb bag of concrete in cubic feet	about 0.60 ft3
Cubic yards from one 80 lb bag	about 0.022 yd3
Cubic inches from one 80 lb bag	about 1,037 cu in
Area at 4 in thick	about 1.8 sq ft
30 sq ft at 4 in	17 bags before waste; 19 with 10% waste
Bags for 1 yd3 before waste	about 45 bags
Bags for 1 yd3 with 10% waste	about 50 bags

Use these as planning shortcuts, then check the yield printed on the exact bag or product page before buying a large quantity.

80 lb bag volume in cubic feet

For concrete estimating, the volume of an 80 lb bag of concrete means the mixed yield after water is added, not the outside package dimensions. A common planning yield is 0.60 cubic feet per 80 lb bag.

Search question	Direct answer
Volume of 80 lb bag of concrete	about 0.60 cubic feet
80 lb concrete bag cubic feet	about 0.60 ft3
80 lb bag concrete cubic inches	about 1,037 cu in
80 lb bag cubic yards	about 0.022 yd3
80 lb bags for 1 cubic yard	about 45 bags before waste

Use the printed yield on the actual product when accuracy matters. High-strength, fast-setting, crack-resistant, or lightweight mixes may not match the standard planning shortcut.

Quick 80 lb bag table

Use this table when you already know the concrete volume. Counts include 10% waste and are rounded up.

Concrete volume	80 lb bags to buy	Approx. dry weight	Planning note
0.10 yd3	5 bags	400 lb	Small repair or a few shallow forms.
0.25 yd3	13 bags	1,040 lb	Practical for many DIY jobs.
0.50 yd3	25 bags	2,000 lb	Stage bags and mixer before starting.
0.75 yd3	38 bags	3,040 lb	Compare delivery, pallet, and mixer rental.
1.00 yd3	50 bags	4,000 lb	Ready-mix should be quoted before buying.
1.50 yd3	75 bags	6,000 lb	Usually a ready-mix or crew-planning decision.

The dry weight is only the material before water. It still has to be loaded, transported, kept dry, opened, mixed, placed, and cleaned up.

80 lb concrete bag yield

Most 80 lb concrete mix bags are estimated at about 0.60 cubic feet of mixed concrete. Always check the yield printed on the product you plan to buy, because specialty mixes can vary.

Bag size	Common yield	Bags for 1 yd3
80 lb	0.60 ft3	45 bags

One cubic yard equals 27 cubic feet:

bags per yard = 27 / 0.60
bags per yard = 45

One cubic foot equals 1,728 cubic inches:

cubic inches per 80 lb bag = 0.60 x 1,728
cubic inches per 80 lb bag = 1,036.8

Rounded for planning, one 80 lb bag yields about 1,037 cubic inches of mixed concrete. That conversion is only a unit change; it does not change the need to verify the printed product yield before a large order.

For a broader comparison of bag sizes, see the Concrete Bags per Yard Guide. For cubic feet per bag across common sizes, use the cubic feet of concrete per bag chart. For the exact one-yard answer, see How Many 80 lb Bags of Concrete Are in a Yard?. For a square-foot coverage table across bag sizes, use the concrete bag coverage calculator for 40, 60, and 80 lb bags. If you are comparing lighter bags, see the 40 lb Concrete Bag Calculator and the 60 lb Concrete Bag Calculator.

Formula for 80 lb bags

Start with project volume in cubic feet:

cubic feet = length ft x width ft x thickness ft

If your thickness is in inches:

cubic feet = length ft x width ft x thickness in / 12

Then divide by the 80 lb bag yield:

80 lb bags needed = cubic feet / 0.60

Add waste before rounding up:

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

A 5% to 10% waste factor is common for simple forms. Uneven bases, deep edges, spills, and measurement uncertainty may need more.

Coverage for one 80 lb bag

Coverage depends on slab thickness.

Thickness	Area from one 80 lb bag
2 in	about 3.6 ft2
3 in	about 2.4 ft2
4 in	about 1.8 ft2
5 in	about 1.4 ft2
6 in	about 1.2 ft2

The formula is:

coverage square feet = 0.60 / thickness ft

At 4 in thick:

0.60 / (4 / 12) = 1.8 ft2

For square-foot coverage tables across 40 lb, 60 lb, and 80 lb bags, see the concrete bag coverage chart by slab thickness.

80 lb bags by common slab size

These examples use 4 inch thickness and 10% waste.

Slab size	Cubic yards with waste	80 lb bags
4x4 slab	0.22 yd3	10 bags
6x6 slab	0.49 yd3	22 bags
8x8 slab	0.87 yd3	40 bags
10x10 slab	1.36 yd3	62 bags
12x12 slab	1.96 yd3	88 bags

For exact slab-specific pages, see Concrete Bags for a 4x4 Slab, Concrete Bags for a 6x6 Slab, Concrete Bags for an 8x8 Slab, and Concrete Bags for a 12x12 Slab.

Example: 30 square feet at 4 inches

Some searches ask a sentence like "how much area does a 80 bag of concrete cover for 30 square feet." The missing piece is usually thickness. At 4 inches thick, 30 square feet is:

30 sq ft x 4 / 12 = 10 ft3

Using the common 0.60 ft3 yield:

10 / 0.60 = 16.7 bags
round up to 17 bags before waste

With 10% waste:

17 x 1.10 = 18.7
round up to 19 bags

Planning estimate: buy 19 bags of 80 lb concrete mix for 30 sq ft at 4 inches if you want a 10% waste allowance. At 2 inches thick the count would be about half that; at 6 inches thick it would be about 50% higher.

Example: 4 ft by 4 ft pad

Assume:

Length: 4 ft
Width: 4 ft
Thickness: 4 in
Waste factor: 10%
Bag yield: 0.60 ft3

Volume:

4 x 4 x 4 / 12 = 5.33 ft3

Bag count before waste:

5.33 / 0.60 = 8.89 bags

Add waste and round up:

8.89 x 1.10 = 9.78
round up to 10 bags

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

Example: 10 ft by 10 ft slab

A 10 ft by 10 ft slab at 4 in thick is:

10 x 10 x 4 / 12 = 33.33 ft3

Using 80 lb bags:

33.33 / 0.60 = 55.55 bags

With 10% waste:

55.55 x 1.10 = 61.11
round up to 62 bags

At this size, compare ready-mix delivery before buying. Sixty-two 80 lb bags is nearly 5,000 lb of dry mix to move, open, mix, and place. For the full 100 square foot comparison across 40 lb, 60 lb, and 80 lb bags, see How Many Bags of Concrete for 100 Square Feet?. If your slab is 10 ft by 10 ft, use the Concrete Bags for a 10x10 Slab Guide. For a smaller square pad, see the Concrete Bags for a 6x6 Slab Guide.

When 80 lb bags make sense

80 lb bags are useful when the project is small enough to mix by hand or with a portable mixer. They can work well for small pads, short repairs, fence posts, mailbox posts, and spots where truck delivery is not practical.

They become less attractive when the bag count gets high, the pour must be placed quickly, or you need consistent finishing time across a larger slab.

For round holes and posts, use the Concrete Post Hole Calculator. For 4x4 fence posts, 6x6 posts, and gate-post bag checks, see the Fence Post Concrete Calculator Guide. For patios, see the Concrete Patio Calculator Guide.

80 lb bag cost and transport checks

Use the actual shelf price and printed yield for the product you plan to buy.

80 lb bagged cost = rounded bag count x price per bag
cost per cubic foot = price per bag / 0.60

If an 80 lb bag costs $6.50:

$6.50 / 0.60 = $10.83 per ft3
$10.83 x 27 = $292.41 per yd3 before waste

That is material only. Add tax, delivery, truck rental, mixer rental, tools, base material, reinforcement, and your time before comparing with a contractor bid or ready-mix invoice.

Before buying dozens of 80 lb bags, confirm:

Vehicle payload and number of store trips.
Whether pallet delivery is available.
How many 80 lb bags the local store puts on one pallet.
Where bags will stay dry before mixing.
Whether the mixer can handle the bag weight per batch.
Whether unopened extra bags can be returned.
Whether the pour must be placed continuously.

For a broader store-cost checklist, see How Much Is a Bag of Concrete?. For pallet counts and full-pallet weight checks, see How Many Bags of Concrete Are on a Pallet?.

Sources and checks

These references are used as planning anchors, then the page converts them into 80 lb bag-specific checkout math.

Source	What to verify
QUIKRETE Concrete Calculator	Product-size yield and bag-count calculator assumptions.
Sakrete Concrete Calculators	Cross-check concrete volume, bag count, and slab inputs.
NRMCA Concrete in Practice guidance	Ready-mix ordering, yield, and jobsite delivery planning concepts.
Local product label or store page	Exact yield, bag count per pallet, return policy, and delivery options.

Use manufacturer data for the product you buy. This guide is a planning check for standard 80 lb bag math, not a replacement for structural design, local code requirements, or the yield printed on the bag.

80 lb vs 60 lb bags

80 lb bags reduce the count but increase the lifting burden. 60 lb bags are easier to handle, but the same volume needs more bags.

Question	80 lb bags may fit	60 lb bags may fit
Is lifting weight a concern?	Only if the crew can handle 80 lb safely.	Better for easier lifting and staging.
Is bag count the main issue?	Fewer bags and fewer openings.	More bags for the same volume.
Is the mixer small?	May need partial bags or careful loading.	Often easier to batch.
Is the price close?	Compare cost per cubic foot.	A sale can make 60 lb bags competitive.

Do not choose only by shelf price. Compare cost per cubic foot, total dry weight, delivery, and the crew's safe handling limit.

Buying checklist

Confirm the yield printed on the 80 lb bag.
Add waste before rounding up to whole bags.
Check whether the mix type fits your project.
Compare total bag weight and mixing time, not only shelf price.
Keep bags dry before mixing.
For large bag counts, compare ready-mix delivery.

FAQ

How much concrete does an 80 lb bag make?

An 80 lb bag of standard concrete mix commonly makes about 0.60 cubic feet of mixed concrete. That equals about 0.022 cubic yards per bag, or about 1.8 square feet at 4 inches thick before waste.

How many cubic inches are in an 80 lb bag of concrete?

Using the common 0.60 ft3 yield, an 80 lb concrete bag makes about 1,037 cubic inches of mixed concrete. The math is 0.60 x 1,728 = 1,036.8.

How many 80 lb bags do I need for 30 square feet?

At 4 inches thick, 30 square feet needs about 17 80 lb bags before waste. With 10% waste, buy about 19 bags. Change the count if your slab thickness is not 4 inches.

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

Using a common 0.60 ft3 yield, one cubic yard takes about 45 bags of 80 lb concrete mix before waste. With 10% waste, plan for about 50 bags. See the one-yard 80 lb bag guide for the waste table.

How much does an 80 lb bag of concrete cover at 4 inches thick?

An 80 lb bag with a 0.60 ft3 yield covers about 1.8 square feet at 4 inches thick.

How many 80 lb bags do I need for a 10 ft by 10 ft slab?

At 4 inches thick, a 10 ft by 10 ft slab needs about 56 bags before waste and about 62 bags with a 10% waste factor.

Should I use 60 lb or 80 lb bags?

80 lb bags reduce the total bag count, but they are heavier to lift and move. For small jobs, choose the bag size you can handle safely and calculate using the yield printed on that product.

How many 80 lb bags are in half a yard?

Half a cubic yard takes about 23 80 lb bags before waste. With 10% waste, plan around 25 bags.

How many 80 lb bags are on a pallet?

Pallet counts vary by store, brand, and region. Check the local product listing or ask the store before planning pickup. For transport, total dry weight is more important than the pallet count. For a cross-size pallet table, see How Many Bags of Concrete Are on a Pallet?.

Can I mix 80 lb bags by hand?

Yes for small quantities, but it becomes hard quickly. For dozens of 80 lb bags, use a rental mixer, stage water and tools first, and compare ready-mix delivery before committing.

Next step

Open the Concrete Bag Calculator to calculate the exact 80 lb bag count for your dimensions. If the result is more than a few dozen bags, compare it with the Ready-Mix vs Bags Calculator.