Work out how many bags of Sakrete concrete you need for a slab, post holes or a known volume. Enter your sizes in metres or feet, pick the product and bag size, and get the bag count, total weight, cubic feet and cubic yards, plus the Australian 20 kg equivalent.
Independent tool. Not made by, approved by or linked with Sakrete, Oldcastle APG or CRH. Sakrete is a trademark of its owner.
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| Bag | Yield | Bags | Total Weight |
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| Product | Bag | Bags |
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Local bags come in 20 kg sizes. Check the yield on the bag you buy.
Bags Needed
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This Sakrete concrete calculator turns your job size into a bag count. It works in metric or US units, so it suits a project in either country.
Using Australian bags instead? Our Concrete Bag Calculator is built around local 20 kg bags. This page is for people who have Sakrete on hand, are working from a US plan, or want to compare it with a local mix.
Sakrete is a long-running American brand of bagged concrete and repair products. A 2026 company release says it was founded in 1936, that it introduced the industry's first bagged concrete mix, and that it is part of Oldcastle APG, a CRH company. It calls Sakrete a North American leader in bagged concrete materials.
The idea of a bagged mix is simple. Cement, sand and stone come pre-blended, and you add water. That suits small jobs where a truck would be too much.
ConcreteCreek is an independent website. We do not sell Sakrete, and this page is not made by, approved by or linked with Sakrete, Oldcastle APG or CRH. Product names are used only to describe which product the figures refer to. Always follow the instructions on your own bag.
Yield is how much concrete one bag makes. These are the figures the calculator uses, with the source for each. Products and bag sizes change, so check your own bag.
| Product | Bag | Yield | Strength | Source |
|---|---|---|---|---|
| High-Strength Concrete Mix | 80 lb | 0.60 cu ft | 4,000 psi | Oldcastle |
| High-Strength Concrete Mix | 60 lb | 0.45 cu ft | 4,000 psi | Same rate as Crack Resistant 60 lb |
| High-Strength Concrete Mix | 40 lb | 0.30 cu ft | 4,000 psi | Our working from the 80 lb yield |
| 5000 Plus Concrete Mix | 80 lb | 0.60 cu ft | 5,000 psi | Oldcastle, catalogue |
| 5000 Plus Concrete Mix | 50 lb | 0.38 cu ft | 5,000 psi | Retailer listing |
| Crack Resistant Concrete Mix | 80, 60 or 50 lb | 0.60, 0.45 or 0.38 cu ft | Not listed | Oldcastle |
| Fast Setting Concrete Mix | 50 lb | 0.38 cu ft | 4,000 psi | Retailer listing |
| Maximizer Concrete Mix | 80 lb | 1.00 cu ft | 5,500 psi | Architect Magazine, Oldcastle |
A few of these need care. The 60 lb and 40 lb yields for the High-Strength mix, and the 60 lb yield for 5000 Plus, are our own working at the same rate per pound. The Maximizer yield comes from a trade article, as the Oldcastle listing we checked gave no yield. The strength for 50 lb 5000 Plus assumes it matches the larger bag. The Sakrete catalogue we found dates from 2018, so sizes may have changed.
Most of these mixes make about 0.0075 cubic feet per pound. Maximizer is the odd one out, as it uses lighter aggregate. One listing calls it a lightweight aggregate and cement mix. So a Maximizer bag weighs the same but fills far more space.
US projects measure concrete in cubic yards. One cubic yard is 27 cubic feet. Australian projects use cubic metres, and one cubic metre is about 35.3 cubic feet. This table shows the bag count before waste.
| Bag | Yield | Per Cubic Yard | Per Cubic Metre |
|---|---|---|---|
| 80 lb | 0.60 cu ft | 45 bags | 59 bags |
| 60 lb | 0.45 cu ft | 60 bags | 79 bags |
| 50 lb | 0.38 cu ft | 72 bags | 93 bags |
| 40 lb | 0.30 cu ft | 90 bags | 118 bags |
| 80 lb Maximizer | 1.00 cu ft | 27 bags | 36 bags |
That first line is why people so often ask about Sakrete bags and cubic yards. For a 0.6 cubic foot bag, one cubic yard is 45 bags, or about 1,630 kg of concrete to lift. See our cubic yards to cubic metres converter for other sizes.
These are common US slab sizes, with 10% waste included.
| Slab | Volume | 80 lb Bags | 60 lb Bags | 80 lb Maximizer |
|---|---|---|---|---|
| 4 ft × 4 ft × 4 in | 5.3 cu ft | 10 | 14 | 6 |
| 8 ft × 8 ft × 4 in | 21.3 cu ft | 40 | 53 | 24 |
| 10 ft × 10 ft × 4 in | 33.3 cu ft | 62 | 82 | 37 |
| 12 ft × 12 ft × 4 in | 48.0 cu ft | 89 | 118 | 53 |
| 10 ft × 10 ft × 6 in | 50.0 cu ft | 92 | 123 | 56 |
| 20 ft × 10 ft × 4 in | 66.7 cu ft | 123 | 163 | 74 |
At 100 mm, the pad is 0.9 m³, or 0.99 m³ with 10% waste. That is 35 cubic feet, so 59 bags of 80 lb. The same job takes about 107 bags of 20 kg Australian premix. At over 2 tonnes, either way, ready-mix is worth a look. Our Concrete Slab Calculator covers the rest of the job.
Coverage depends on thickness. Divide the yield by the thickness to find the area one bag covers. These are for a standard bag, before waste.
| Thickness | 80 lb Bag | 60 lb Bag | 50 lb Bag |
|---|---|---|---|
| 2 in (50 mm) | 3.6 sq ft (0.34 m²) | 2.7 sq ft (0.25 m²) | 2.3 sq ft (0.22 m²) |
| 3 in (75 mm) | 2.4 sq ft (0.23 m²) | 1.8 sq ft (0.17 m²) | 1.5 sq ft (0.14 m²) |
| 4 in (100 mm) | 1.8 sq ft (0.17 m²) | 1.35 sq ft (0.13 m²) | 1.14 sq ft (0.11 m²) |
| 6 in (150 mm) | 1.2 sq ft (0.11 m²) | 0.9 sq ft (0.08 m²) | 0.76 sq ft (0.07 m²) |
So at 4 inches, an 80 lb bag covers only about 1.8 square feet. That surprises many first-timers. It also shows why thickness matters so much. Going from 4 to 6 inches uses 50% more bags on the same slab. Metric figures are rounded, and use the metric thickness shown, so they differ slightly from an exact inch conversion.
The High-Strength listing says the mix is for jobs at least 2 inches thick. Most slabs that carry people use more than that. Our Concrete Slab Thickness Guide explains how to choose.
Post holes are a classic job for bagged concrete. The calculator works out the hole, then takes away the post.
A 10 inch hole that is 36 inches deep holds 1.64 cubic feet. A 4 inch square post takes up 0.33 cubic feet of that, which leaves 1.30. With 10% waste, that is 1.43 cubic feet. At 0.6 per bag, that is 2.4, so 3 bags of 80 lb for one post. Ten posts share the bags, so they need 24 bags, not 30.
Six holes, each 300 mm wide and 900 mm deep, with 100 mm square posts, come to 0.33 m³. With 10% waste, that takes 22 bags of 80 lb, or 39 bags of 20 kg Australian premix.
Real holes are rarely neat, so measure a few. For treated pine posts, check that the post is rated for ground contact. Our Concrete Post Hole Calculator goes into more detail.
The calculator handles slabs and post holes directly. For anything else, work out the volume, then use Known Volume. These formulas cover the common shapes.
| Job | Formula In Feet | Example | Volume | 80 lb Bags With 10% |
|---|---|---|---|---|
| Round Column | 3.14 × dia² ÷ 4 × height | 12 in wide, 4 ft high | 3.14 cu ft | 6 |
| Strip Footing | Length × width × depth | 20 ft × 1 ft × 1 ft | 20 cu ft | 37 |
| Square Pier | Width × width × depth | 2 ft × 2 ft × 1 ft | 4 cu ft | 8 |
| Step | Run × rise × width | 1 ft × 0.5 ft × 4 ft | 2 cu ft | 4 |
For the step, add each step together, as lower steps sit under the ones above. Our Concrete Steps Calculator handles this for you, and our Concrete Footing Calculator does the same for footings. To enter a volume in cubic feet here, divide by 27 to get cubic yards, as 20 cubic feet is 0.74 cubic yards.
If a job has several parts, our Concrete Computation Calculator adds them up and shows each step. Then enter the total here.
You can do the sum by hand in four steps. This is how the calculator works.
In metric, multiply cubic metres by 35.3147 to get cubic feet first. Or use litres, as 1 cubic foot is about 28.3 litres. So a 0.6 cubic foot bag makes about 17 litres, a 0.45 bag about 12.7 litres, and a 0.38 bag about 10.8 litres.
Always round the bag count up. A part bag is not sold. Unopened spares can often go back to the store, as Bunnings notes for its own bags, so keep them dry and keep your receipt.
All the standard bags give about the same concrete per kilogram, so the total weight barely changes. For a 10 ft × 10 ft slab, it is about 2.2 tonnes in any size. What changes is how many lifts you make, and what each lift weighs.
| Bag | Weight | Makes About |
|---|---|---|
| 80 lb | 36.3 kg | 17.0 L |
| 60 lb | 27.2 kg | 12.7 L |
| 50 lb | 22.7 kg | 10.8 L |
| 40 lb | 18.1 kg | 8.5 L |
An 80 lb bag is heavy for one person. Local Australian bags are usually 20 kg, which is much easier to handle. If you are working alone, or moving bags up steps, a smaller bag can be easier on your back, even if you buy more of them. Check the cost per cubic foot too, as prices differ.
| Job | Product To Look At | Why |
|---|---|---|
| Slabs, Paths, Footings | High-Strength | Listed for driveways, patios, footings, steps and more |
| Heavy-Duty Work | 5000 Plus | Listed for heavy-duty work over 2 inches thick, and cold weather |
| Slabs Needing Less Surface Cracking | Crack Resistant | Fibres help reduce surface cracking |
| Fence Posts And Quick Repairs | Fast Setting | Sets faster than ordinary concrete |
| Long Carries Or Fewer Bags | Maximizer | More concrete from each bag |
The Crack Resistant listing says foot traffic is possible after 24 hours, and vehicle traffic after 72 hours. It also says the fibres can reduce the need for rebar or mesh. Do not skip steel on any job where plans call for it. The catalogue says Fast Setting Concrete Mix sets in about 30 minutes. For structural work, follow your engineer, as they set the grade and reinforcement.
US products list strength in pounds per square inch, or psi. Australian concrete uses megapascals, or MPa. To convert, multiply psi by 0.0069.
| Listed Strength | In MPa | Nearest Common Australian Grade Below |
|---|---|---|
| 4,000 psi | 27.6 MPa | N25 |
| 5,000 psi | 34.5 MPa | N32 |
| 5,500 psi | 37.9 MPa | N32 |
The grade column is only a rough guide, as US and Australian test rules differ. So a psi rating does not prove a product meets an Australian grade. If your plans call for N25 or N32, order that grade, and read Concrete Grades Explained for what it means.
We found no Australian stockist for Sakrete, and the brand describes itself as North American. So if you are in Australia, a local bag will be simpler. Here is how the local option compares.
| Bag | Weight | Makes About | Bags Per m³ |
|---|---|---|---|
| Sakrete 80 lb | 36.3 kg | 17.0 L | 59 |
| Sakrete 50 lb | 22.7 kg | 10.8 L | 93 |
| Australian 20 kg Premix | 20 kg | 9.3 L | 108 |
The 20 kg yield comes from the Dingo MaxPRO listing. The rate per kilogram is almost the same as Sakrete's, at about 0.47 litres per kg. So a quick rule is that one 80 lb bag is about two 20 kg bags.
For fast setting work, Bunnings lists Dingo Fast Set Hi Strength Concrete at $14.22 for 20 kg, at 40 MPa, setting in about 15 minutes. That is one current listing, so check your local price. Compare other brands on the shelf too. Our Concrete Bag Yield Calculator works out yields for any bag.
Bags are great for small jobs. But the numbers climb quickly. One cubic metre takes 59 bags of 80 lb, which is over 2 tonnes to lift, mix and place. Concrete also starts to stiffen as you work, so a slow pour can leave joints where batches meet.
As a rule of thumb, once you pass about half a cubic metre or so, look at ready-mix, or at least hire a mixer and get help. That limit is our own guide. In Australia, ready-mix suppliers can charge small-load fees, so compare both. Use our Concrete Order Calculator and Concrete Cost Calculator to check. In the US, a short-load fee often applies too, so ask your supplier.
Sakrete prices vary by store and country, so the calculator leaves the price to you. Enter your bag price under Waste And Price. It multiplies the price by the bag count, in whatever currency you use.
To compare bags fairly, use the cost per cubic foot, or per litre. Divide the bag price by the yield. So a bag at $7 with a 0.6 cubic foot yield costs $11.67 per cubic foot. A Maximizer bag at $10 with a 1 cubic foot yield costs $10 per cubic foot, even though the bag price is higher. Those prices are only examples, so use your own.
Bags cost far more per cubic metre than ready-mix. At the $14.22 Bunnings listing above, and 0.0093 m³ per bag from another listing, a cubic metre takes 108 bags, or about $1,536. What's The Damage lists delivered 25 MPa ready-mix at a typical $380 per m³. The two products differ, and small-load fees apply to small orders, so it is only a rough comparison. But it shows why bags suit small jobs, and only small jobs. Our Concrete Cost Per Square Metre page goes further.
Bag counts are only half the job. Think about how the bags get to the pour.
| Bag | Bags Per Pallet | Pallet Weight | Source |
|---|---|---|---|
| 80 lb Maximizer | 35 | About 1,270 kg | Oldcastle |
| 50 lb 5000 Plus | 64 | About 1,452 kg | Retailer listing |
That is far more than most cars and utes can carry in one trip, so check your vehicle's payload, or ask for delivery. Pallets also need firm, flat ground, and a way to get the bags from the kerb to the job.
Keep bags dry and off the ground. Bunnings says to store spares somewhere dry and off the ground. Damp bags can set hard, so do not use any bag with hard lumps. Plan your mixing too. The Maximizer listing gives a working time of about 25 minutes, so have everything ready, and work in small batches. Two people working together, with one mixing and one placing, is usually the minimum for a slab.
Much of the advice online for Sakrete is American. It uses feet, inches, cubic yards and psi, and it is built around US codes and climates. If you are following a US guide in Australia, keep a few things in mind.
| US Term | Australian Term | Conversion |
|---|---|---|
| Cubic Yard | Cubic Metre | 1 cu yd = 0.765 m³ |
| Cubic Foot | Litres | 1 cu ft = 28.3 L |
| 4 Inch Slab | 100 mm Slab | 4 in = 101.6 mm |
| 4,000 psi | 27.6 MPa | Multiply by 0.0069 |
| Rebar #4 | N12 Is Closest | #4 is about 12.7 mm |
| Sonotube | Round Column Form | Same use |
Footing rules, frost depths and steel sizes all differ between countries. Australia has no frost problem in most places, but it has reactive clay, so local slabs follow local standards. So use a US video to learn the method, and use your plans and local rules for the sizes. Licensing rules also differ, and in Australia some concrete work needs a licensed builder or a permit. Check with your council or state regulator.
The bag instructions come first, as water amounts differ by product. The listings we checked said only to add water, so we have not given a water figure. These general steps come from Concrete Basics and common practice.
Our guide on how to pour a concrete slab walks through the whole job.
Wet concrete can burn skin, and dry cement dust irritates the eyes and lungs. Wear gloves, boots, eye protection and a mask. Lift with care, as an 80 lb bag is over 36 kg. Cutting cured concrete creates dust that contains silica. See Safe Work Australia for more.
Before you buy a car load of bags, do a quick check. It only takes a minute, and it catches most errors.
Standard 80 lb bags from other US brands are often close to 0.6 cubic feet, but do not assume it. Read the bag, then enter a known volume here and adjust. Lightweight and high-yield mixes can differ by a lot, as Maximizer shows.
A bag count tells you how much to buy. It does not tell you whether the slab, footing or wall is the right size. Anything that carries a structure, a vehicle or a retaining load should follow engineered plans. For a house footing, a tall wall or a suspended slab, talk to an engineer first, and order a graded ready-mix. For small pads, posts and repairs, a bag calculator is usually all you need.
If you have measured on site in mixed units, our Concrete Measurement Calculator can help.
About 45. A cubic yard is 27 cubic feet, and an 80 lb bag of Sakrete High-Strength Concrete Mix yields about 0.6 cubic feet, so 27 ÷ 0.6 = 45 bags, before waste.
About 60. A 60 lb bag yields about 0.45 cubic feet, so 27 ÷ 0.45 = 60 bags, before waste.
It yields about 0.6 cubic feet. At 4 inches thick, that covers about 1.8 square feet. In metric, it makes about 17 litres, which covers about 0.17 m² at 100 mm.
A 10 ft × 10 ft slab at 4 inches thick is 33.3 cubic feet. With 10% waste, that takes 62 bags of 80 lb Sakrete High-Strength mix.
A 10 inch hole, 36 inches deep, with a 4 × 4 post takes about 3 bags of 80 lb mix, with 10% waste. Enter your own hole size, as a small change in width makes a big difference.
A trade article says an 80 lb bag makes one full cubic foot, so it covers much more than a standard bag. The Oldcastle listing we checked did not state a yield, so read your bag.
Listings give 4,000 psi for High-Strength and Fast Setting mixes, 5,000 psi for 5000 Plus and 5,500 psi for Maximizer. That is about 28, 34 and 38 MPa.
We found no Australian stockist. Sakrete describes itself as a North American brand. In Australia, look for local 20 kg bags such as those from Dingo, Bastion and Boral.
Local 20 kg premix bags do the same job. An 80 lb bag weighs about 36 kg, which is close to two 20 kg bags. One listing gives 0.0093 m³ for a 20 kg bag, so two bags make about 18.6 litres, against about 17 litres for an 80 lb bag.
No. This is an independent calculator from ConcreteCreek. It is not made by, approved by or linked with Sakrete or its owners. Yields come from published listings.
The calculator starts at 10%. Concrete Basics says to order about 10% extra, and Bunnings suggests 5% to 10%.
No. Your numbers stay in your browser and nothing is uploaded. Use Download Estimate to keep a copy.
Figures reviewed November 2026. Sources: Oldcastle APG, Sakrete catalogue, Architect Magazine, retailer listings, Bunnings, What's The Damage, Concrete Basics and Safe Work Australia. ConcreteCreek is independent, and Sakrete is a trademark of its owner. Read our Disclaimer and Calculator Methodology.