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

45 bags. An 80 lb bag yields 0.60 cubic feet of mixed concrete and a cubic yard is 27 cubic feet, so 27 / 0.60 = 45 bags.

How many 60 lb bags make a cubic yard?

60 bags. A 60 lb bag yields 0.45 cubic feet, and 27 / 0.45 = 60. A 50 lb bag yields 0.375 cubic feet (72 per yard) and a 40 lb bag yields 0.30 cubic feet (90 per yard).

How much water does a bag of concrete need?

Roughly 3 quarts for a 60 lb bag and 4 quarts for an 80 lb bag, added gradually. Add the last of it slowly — excess water is the single easiest way to weaken a mix and cause surface dusting.

How many bags of concrete for a 4x4 post hole?

A 12 inch diameter hole 30 inches deep holds about 2.1 cubic feet after subtracting a 4x4 post, so 4 bags of 80 lb mix or 5 bags of 60 lb mix per hole.

Concrete Bag Calculator

Turn a slab, column or plain volume into a bag count for every US bag size, with the mixing water, total weight and cost worked out.

Quick answer

You need 20 bags of 80 lb concrete mix — 11.7 cubic feet including 10% waste, about 1,600 lb of product and $150 at $8 a bag. One cubic yard takes 45 bags of 80 lb, 60 bags of 60 lb or 90 bags of 40 lb mix.

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What are you pouring?

Input

Length(ft)

Width(ft)

Thickness(in)

Waste(%)

Bag size(lb)

Price per bag($)

bags = ceil(volume ft³ x (1 + waste) / bag yield ft³)

Bags to buy

80 lb bags

1,600 lb of product

Volume with waste

11.7cu ft

In cubic yards

0.43yd³

Bag cost

$150

Above about 1 cubic yard (not this pour), ready-mix is usually cheaper and far less work.

Every bag size

Bag	Yield	Per yd³	Bags needed
40 lb	0.3 ft³	90	40
50 lb	0.375 ft³	72	32
60 lb	0.45 ft³	60	27
80 lb	0.6 ft³	45	20

Yields are the nominal values published on US bagged concrete mix.

Published figure

Bag yields and what they mean

Bagged mix is sold by dry weight, not by finished volume, and roughly 133 lb of dry mix makes one cubic foot of placed concrete. That is where the published yields come from: 80 lb gives 0.60 ft³, 60 lb gives 0.45 ft³, 50 lb gives 0.375 ft³ and 40 lb gives 0.30 ft³.

Mixing by hand caps out fast. A 60 lb bag is about 45 lb of lifting per shovel cycle, and a cubic yard is 60 of them — most people top out around 15 to 20 bags before the first batch starts setting harder than the last. Rent a mixer above ten bags, or order a truck.

Bag size	Yield (ft³)	Bags per yd³	Bags per ft³	Water (approx)
40 lb	0.3	90	3.33	2 quarts
50 lb	0.375	72	2.67	2.5 quarts
60 lb	0.45	60	2.22	3 quarts
80 lb	0.6	45	1.67	4 quarts

Bags per cubic yard and per cubic foot, plus typical mixing water.

Source & method: Bag counts are computed from published nominal yields; mixing water is the common guideline of roughly one quart per 20 lb of dry mix, added gradually to reach a workable, not soupy, consistency.

Mixing gear

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Frequently asked questions

How many 80 lb bags of concrete are in a cubic yard?: 45 bags. An 80 lb bag yields 0.60 cubic feet of mixed concrete and a cubic yard is 27 cubic feet, so 27 / 0.60 = 45 bags.
How many 60 lb bags make a cubic yard?: 60 bags. A 60 lb bag yields 0.45 cubic feet, and 27 / 0.45 = 60. A 50 lb bag yields 0.375 cubic feet (72 per yard) and a 40 lb bag yields 0.30 cubic feet (90 per yard).
How much water does a bag of concrete need?: Roughly 3 quarts for a 60 lb bag and 4 quarts for an 80 lb bag, added gradually. Add the last of it slowly — excess water is the single easiest way to weaken a mix and cause surface dusting.
How many bags of concrete for a 4x4 post hole?: A 12 inch diameter hole 30 inches deep holds about 2.1 cubic feet after subtracting a 4x4 post, so 4 bags of 80 lb mix or 5 bags of 60 lb mix per hole.