Cement Calculator: Bags of Portland Cement for Concrete
A cubic yard of 1:2:3 concrete needs about 7 bags of 94 lb Portland cement (27 ft³ × 1.54 ÷ 6 = 6.93 ft³ of cement), an estimate based on rule-of-thumb factors.
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11 bags of 94 lb cement
- Dry materials (× 1.54)
- 73.92 ft³
- Cement
- 10.56 ft³
- Sand
- 21.12 ft³
- Gravel
- 42.24 ft³
Key takeaways
- About 7 bags of 94 lb Portland cement per yard of 1:2:3 concrete.
- About 6 bags per yard of 1:2:4.
- About 10 bags per cubic meter of 1:2:3.
- Cement is one ingredient; concrete mix bags already contain sand and gravel.
How Many 94 lb Bags of Portland Cement Make a Yard of Concrete?
About 7 bags of 94 lb Portland cement make one cubic yard of 1:2:3 concrete, and about 6 bags make a yard of leaner 1:2:4 concrete. The figure uses a 1.54 dry-volume factor and about 1 ft³ per 94 lb bag, both secondary rules of thumb, so treat it as an estimate.
Cement vs Concrete: What Is the Difference?
Cement is one ingredient of concrete: Portland cement binds sand and gravel once water is added. A bag of concrete mix already contains all three, so 45 bags of 80 lb concrete mix make a yard, while 7 bags of cement make a yard only with sand and gravel added. Count premix with the bags of concrete calculator.
Bags of Cement per Cubic Meter
One cubic meter of 1:2:3 concrete needs about 10 bags of 94 lb cement: 35.31 ft³ × 1.54 ÷ 6 = 9.06 ft³, rounded up.
How to Calculate Bags of Cement for a Slab
- Find the slab volume in cubic feet with the concrete slab calculator.
- Enter it in the cement calculator above and pick the ratio.
- Round the cement bags up to whole bags.
Get the volume for any slab size from the concrete pad calculator.
A 10×10 ft slab at 4 in (33.33 ft³) needs 9 bags of 94 lb cement at 1:2:3.
Worked Examples: Cement for Three Pours
One yard of 1:2:3. 27 × 1.54 ÷ 6 = 6.93 ft³ of cement = 7 bags of 94 lb.
A 12×12 ft slab at 4 in (48 ft³). 48 × 1.54 ÷ 6 = 12.3 ft³ = 13 bags of 94 lb.
A 20 ft footing, 12×6 in (10 ft³). 10 × 1.54 ÷ 6 = 2.57 ft³ = 3 bags of 94 lb.
Sand and Gravel With Your Cement
| Concrete | Cement (94 lb bags) | Sand (ft³) | Gravel (ft³) |
|---|---|---|---|
| 1 yd³ at 1:2:3 | 7 | 13.86 | 20.79 |
| 1 yd³ at 1:2:4 | 6 | 11.88 | 23.76 |
These come from the 1.54 dry-volume rule of thumb and about 1 ft³ per bag of cement, so treat them as estimates.
Portland Cement vs Concrete Mix Bags
Choose Portland cement when you mix large amounts on site and have sand and gravel; choose premix concrete bags for small jobs, since a 1:2:3 yard needs 7 bags of cement plus about 35 ft³ of aggregate, while premix needs 45 bags of 80 lb and only water.
Cement Bags for Fence Posts
A 4×4 post in a 12 in hole 2 ft deep needs 1.40 ft³ of concrete, about ⅓ bag of 94 lb cement at 1:2:3 plus sand and gravel; most people use premix instead, 3 bags of 80 lb concrete mix per post. See the fence post concrete calculator.
Cement Calculator FAQ
How many 50 lb bags of concrete equal 1 yard?
72 bags of 50 lb concrete mix make one cubic yard; that is premix, not Portland cement.
How many 94 lb bags of Portland cement make a yard of concrete?
About 7 bags of 94 lb Portland cement make a cubic yard of 1:2:3 concrete.
How many bags of cement for a 4×4 slab?
A 4×4 ft slab at 4 in (5.33 ft³) needs about 1.4 ft³ of cement at 1:2:3, or 2 bags of 94 lb rounded up.
Is it cheaper to buy bags of concrete or mix your own?
For small jobs premix bags are simplest; mixing your own from cement, sand and gravel needs about 7 bags of 94 lb cement plus aggregate per yard, and above about 1 yd³ ready-mix is usually cheapest. See ready-mix vs bagged concrete.
Which is better, cement or concrete?
Neither on its own: cement is the binder inside concrete, and concrete (cement, sand, gravel and water) is what you pour for slabs, footings and sidewalks.
Are sidewalks cement or concrete?
Sidewalks are concrete; cement is one ingredient of that concrete.
Next step
Work out sand and gravel too with the concrete mix ratio calculator, or compare with premix on bags of concrete per yard.
Official sources
Last reviewed 2026-11-05. Numbers come from our tested engine; see how we calculate and our sources.