How Many 80lb Bags of Concrete Make a Yard?

The short answer

A cubic yard of concrete requires 45 standard 80-pound bags. Each bag yields 0.6 cubic feet of mixed concrete. For real projects, always round up and add a 5-10% overage. Check your specific mix. Some high-strength formulas yield slightly less.

Key takeaways

Direct conversion: 45 eighty-pound bags make one cubic yard of concrete.
Project planning: Always add 5-10% extra for waste, spillage, and subgrade variations.
Cost snapshot: Bags cost $4 to $9 each, as of January 2025, so a yard runs $180 to $405 in materials.
DIY readiness: Mixing 45 bags by hand is backbreaking. Rent a mixer for pours larger than a few bags.

Bagged concrete is perfect for small to mid-size jobs like setting posts or pouring a patio. But guessing the number of bags leads to extra store runs or wasted cash. This guide gives you the exact number, shows how to calculate your own project, and shares pro tips to do it right.

How Many 80lb Bags of Concrete Are in a Yard?

The short answer is 45 bags per cubic yard. That's based on the standard yield of 0.6 cubic feet for a typical 80 lb bag of concrete mix like Quikrete. A cubic yard contains 27 cubic feet, so 27 ÷ 0.6 = 45 bags exactly.

80 lb bags are the most common size for DIY work.
40 lb bags yield about 0.3 cu ft, so you'd need 90 per yard.
60 lb bags yield about 0.45 cu ft, requiring 60 per yard.
Always check the label. Some specialty mixes yield a little less.
Use our bagged concrete calculator to get an exact count for your dimensions.

How Do You Calculate Bags of Concrete for a Project?

Start by measuring the volume of concrete you need in cubic feet, then convert to bags. For slabs, multiply length × width × thickness (in feet). For post holes, use cylinder volume.

Measure accurately: length, width, and depth in feet.
Volume in cubic feet: length × width × (thickness in inches ÷ 12).
Convert to cubic yards: divide cubic feet by 27.
For 80 lb bags: multiply the cubic feet by 1.667 (or divide by 0.6). Or, multiply the cubic yards by 45.
Add overage: multiply your total bag count by 1.05 to 1.10.
See the concrete slab calculator for a step-by-step tool.

What Does It Cost to Buy 45 Bags of Concrete?

Bag prices change by brand, store, and region. As of January 2025, one 80 lb bag of standard concrete mix runs $4 to $9. That puts a full yard of bagged concrete between $180 and $405 in material costs.

Basic 80 lb bag: $4 to $6 each for general-purpose mix.
High-strength or crack-resistant 80 lb bag: $6 to $9 each.
Buying in bulk or during sales can save 10-15%.
Delivery fees apply if you order online; pickup is usually free.
Your local big-box store often has the best everyday price.
For a total project cost estimate, try our bagged concrete calculator.

How Much Extra Concrete Should You Order?

Always order 5-10% more bags than your exact calculation. Uneven ground, spillage during mixing, and slight measuring errors eat up material. Running out midway ruins a pour.

Subgrade unevenness can add 5% or more to the depth.
Spillage and mixing waste easily account for another 5%.
For a 10×10 slab needing 56 bags exactly, buy 60 to 62 bags.
Deck footings and round forms waste a little more, so lean toward 10% overage.
Combine leftover dry bags to fill low spots or for small repairs later.
Use the concrete slab calculator to see the overage built in.

Are All 80lb Concrete Bags the Same?

Not exactly. Standard 80 lb concrete mixes all produce around 0.6 cu ft, but specialty mixes can have different yields. Check the bag before you rely on the 45‑bag rule.

Standard Quikrete or Sakrete: 0.6 cu ft yield, 45 bags per yard.
High-strength 5000 psi mix: often yields 0.45 cu ft. That's 60 bags per yard.
Fast-setting mix: yield may vary, but usually close to standard.
Crack-resistant or fiber-reinforced: yields typically match standard.
Always read the yield statement on the bag, usually printed near the weight.
For footings, see our concrete tube calculator.

Should You Mix 45 Bags of Concrete by Hand?

For more than about 10 bags, the answer is usually no. Mixing by hand with a wheelbarrow and hoe is exhausting and hard to keep consistent. Renting a mixer is affordable and saves your back.

Under 10 bags: hand mixing is doable. Work in small batches.
10 to 30 bags: rent a small electric mixer for about $40 to $70 per day.
30+ bags or a large slab: consider ready-mix concrete delivery. It's more efficient and often cheaper per yard.
Ready-mix trucks deliver exactly what you need, no mixing labor.
For a perfect slab, use our concrete slab calculator to help you decide between bags and ready-mix.

Bags per cubic yard	45	60
Yield per bag	0.6 cu ft	0.45 cu ft
Cost per bag	$4 – $9	$3 – $7
Total material cost per yard	$180 – $405	$180 – $420

Questions this page answers

How much water do I need per 80 lb bag?

Typically 6 to 9 pints of water per 80 lb bag, but always check the bag. Start with less and add gradually while mixing. Too much water weakens concrete. Follow the manufacturer's instructions for the best results.

Can I mix a partial bag of concrete?

Yes, you can mix a partial bag. Weigh or measure the dry mix accurately, then mix only what you need. Store the rest in a sealed container in a dry place. It can last for months if moisture stays out.

How long does a mixed bag of concrete last?

Mixed concrete stays workable for about 30 to 60 minutes, depending on the weather. Hot temperatures speed up setting, so you have less time. Cold weather slows it down. Plan your pour to use the mix right away.

Is bagged concrete as strong as ready-mix?

Yes, bagged concrete is as strong as ready-mix when mixed and cured correctly. Both meet industry strength standards. However, ready-mix is more consistent for large volumes because it is blended at the plant.

How many 80lb bags for a 4x4 post hole?

For a typical 4x4 post hole 12 inches wide and 24 inches deep, you need about 1.6 cubic feet of concrete. That's roughly 3 eighty-pound bags. Use our concrete tube calculator for an exact count based on your hole size.

What happens if I use fewer bags than needed?

Using fewer bags than needed can lead to a slab that is too thin, which cracks under weight. For posts, insufficient concrete may not hold the post steady. Always measure carefully and include overage to avoid these problems.

Can I mix 80 lb bags in a 5-gallon bucket?

Mixing an 80 lb bag in a 5-gallon bucket is difficult. A wheelbarrow is the standard tool. A bucket holds only about two-thirds of a bag, so you would need to split the mix and risk inconsistent concrete. Use a wheelbarrow or a mixing tub.

So, how many 80lb bags of concrete in a yard? The answer is 45 bags, based on a standard yield of 0.6 cubic feet per bag. For your own project, measure carefully, add 5-10% overage, and decide between mixing yourself and calling a pro. Plug your dimensions into our concrete bags calculator to get an instant, accurate bag count.