Sakrete Concrete Calculator
Enter your slab size to get the cubic feet of concrete and how many 80 lb or 60 lb bags of Sakrete you need.
What your result means
The 80 lb bag count is your main number, since 80s are cheaper per yard for anything sizable. The 60 lb count is there if you'd rather lift lighter bags. Buy about 10% over either figure for spillage and odd corners, and once you're past a cubic yard, ready-mix delivered is usually cheaper than bags.
How to use this calculator
- Measure length, width, depth.
- Read bags needed (both 80 lb and 60 lb sizes shown).
- Buy 10% extra for spillage and odd corners.
- Mix in a wheelbarrow or rented mixer.
- Use 80 lb bags for large jobs - cheaper per yard.
The formula
Volume in cubic feet is length times width times depth in feet. An 80 lb bag yields 0.6 cubic feet and a 60 lb bag yields 0.45, so divide the volume by the bag yield and round up.
Worked example
Say you're pouring a 6 by 3 ft slab 4 inches deep. That's 6 cubic feet, which is 10 bags of 80 lb Sakrete or 14 of the 60 lb. Round up to 11 of the 80s to give yourself a 10% cushion.
Sakrete bag yield
| Bag | Yield | Bags per cubic yard |
|---|---|---|
| 80 lb | 0.6 cf | 45 |
| 60 lb | 0.45 cf | 60 |
| 40 lb | 0.3 cf | 90 |
Tips & gotchas
- An 80 lb bag yields 0.6 cubic feet; a 60 lb bag yields 0.45.
- Past a cubic yard (about 45 bags), ready-mix delivered is usually cheaper.
- Use exactly the water on the bag label. Too wet and the concrete loses strength.
- Pour within about 30 minutes of mixing, before it starts to set.
- Cure it 7 days minimum, 28 for full strength.
Frequently asked questions
How many 80 lb bags of Sakrete in a yard?
45 bags. Above a yard, ordering ready-mix usually makes more sense.
How much water for an 80 lb bag of Sakrete?
About 6 pints, or 3 quarts. Always check the bag.
How long does Sakrete take to cure?
Walkable in 24 to 48 hours, full strength at 28 days.
Can I add water to extend the working time?
No. Extra water weakens the concrete a lot. Mix only what you can place.
What's the difference between concrete mix and cement?
Concrete is cement plus sand and gravel. Cement alone is just the binder.
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