How Many Concrete Bags Are There in a Yard?

If you’ve ever stood in a hardware store staring at stacks of concrete mix bags, wondering “How many of these do I need to make one cubic yard of concrete?” — you’re not alone.

Contractors, DIYers, and even suppliers often need quick conversions between bag counts and cubic yard volume to plan materials, estimate costs, or schedule a pour efficiently.

This guide breaks down exact bag counts per cubic yard for every common mix size — 40 lb, 50 lb, 60 lb, 80 lb, and 20 kg bags — along with field-tested math and quick reference tables for real-world use.

Why “Bags per Yard” Matters

One cubic yard of concrete equals 27 cubic feet of material.
But bagged concrete mixes (like those from Quikrete or Sakrete) yield far less than a full cubic foot per bag — the actual yield depends on bag weight and mix composition.

Knowing how many bags make up a yard helps you:

Plan and budget concrete for slabs, posts, or footings
Compare mix types or bag sizes for cost efficiency
Avoid running short mid-pour — one of the most common jobsite mistakes

You can also verify this easily with the Concrete Bags Calculator, which applies these same yield conversions automatically.

Step 1 — Understanding Bag Yields

Each bag of pre-mixed concrete produces a certain volume when combined with water. The yield depends on the mix density and aggregate content.

Below is the average yield of each bag size based on standard manufacturer data:

Bag Weight	Yield (ft³)	Bags per Cubic Yard (27 ft³)
40 lb	0.30	90
50 lb	0.375	72
60 lb	0.45	60
80 lb	0.60	45
20 kg (metric)	0.33	82

These values assume a properly mixed batch with no water excess and good compaction. Small field variations (±5%) are normal due to air entrainment, moisture, and mixing technique.

Step 2 — The Formula for Bags per Yard

If you want to calculate it yourself, here’s the formula:

Bags = Volume (yd³) × (27 ÷ Bag Yield)

Since each cubic yard equals 27 cubic feet, dividing 27 by the bag yield gives you the number of bags needed per yard.

Example:

For 60 lb bags (0.45 ft³ yield):

Bags = 1 × (27 ÷ 0.45) = 60 bags per cubic yard

If you need half a yard of concrete:

Bags = 0.5 × 60 = 30 bags

Simple and reliable — this is the same math used by ready-mix estimators and concrete suppliers.

Step 3 — Example Calculations for Common Projects

Let’s look at a few practical examples to see how “bags per yard” applies in real work scenarios.

Example 1 — Small Patio Slab

You’re pouring a 10 ft × 10 ft slab, 4 inches thick.

Volume = 10 × 10 × 0.333 = 33.3 ft³ 33.3 ÷ 27 = 1.23 yd³

For 80 lb bags (45 bags/yd³):

Bags = 1.23 × 45 = 55.4 → round to 56 bags

For 60 lb bags (60 bags/yd³):

Bags = 1.23 × 60 = 73.8 → round to 74 bags

So, you’ll need about 56 of the 80 lb bags or 74 of the 60 lb bags.

Example 2 — Fence Posts

You’re setting 10 posts, each hole requiring 1.25 ft³ of concrete.

Total volume = 10 × 1.25 = 12.5 ft³ = 12.5 ÷ 27 = 0.46 yd³

For 60 lb bags: 0.46 × 60 = 27.6 → 28 bags

For 80 lb bags: 0.46 × 45 = 20.7 → 21 bags

Always add one or two extra bags to cover spillage or uneven holes.

Example 3 — Garage Footings

A footing measures 2 ft wide × 1 ft thick × 40 ft long.

Volume = 2 × 1 × 40 = 80 ft³ 80 ÷ 27 = 2.96 yd³

For 80 lb bags (45/yd³):

2.96 × 45 = 133.2 → round to 134 bags

That means roughly 134 of the 80 lb bags or 178 of the 60 lb bags for the same pour.

Quick Reference — Bags per Yard and Fractional Yards

Here’s a compact chart showing approximate bag counts for different yardages.

Bag Weight	¼ Yard	½ Yard	¾ Yard	1 Yard	1½ Yards
40 lb	23	45	68	90	135
50 lb	18	36	54	72	108
60 lb	15	30	45	60	90
80 lb	11	23	34	45	68
20 kg	21	41	62	82	123

Tip: For small pours (under ½ yard), consider fast-setting mixes in 50–60 lb bags — they’re easier to handle and ideal for patching, steps, or post bases.

Step 4 — Choosing Bag Size for Your Project

Each bag size offers a balance between handling ease and mixing efficiency:

Bag Size	Pros	Cons
40 lb	Easy to lift, good for small work	More bags = more mixing time
50 lb	Common in DIY use, moderate handling	Slightly lower yield
60 lb	Best balance for most users	Heavier for long jobs
80 lb	Fewer bags, faster batching	Heavy to carry and mix manually
20 kg (metric)	Common in UK, AU, CA markets	Moderate yield per bag

For hand-mixed jobs, most pros prefer 60 lb or 80 lb mixes. For wheelbarrow or portable mixer batches, heavier bags reduce total mixing cycles.

Step 5 — Waste and Overfill Allowance

Even when math is perfect, concrete isn’t.
Rough subgrade, uneven forms, or over-troweling can all consume more material than expected.

A smart contractor always adds 5–10% extra for these real-world variables.

Adjusted Bags = Bags × 1.05 (for 5% waste)

Example:
If you calculated 60 bags exactly for 1 yard:
60 × 1.05 = 63 bags → keep 3 extra on site

That small buffer prevents an emergency run mid-pour.

Step 6 — When to Consider Ready-Mix Instead

Bagged concrete is ideal for small to medium pours (up to about 1–1.5 yards).
Beyond that, it becomes labor-intensive and sometimes more expensive than ordering ready-mix.

Rule of thumb:

Up to 1 yd³ — bagged mix is fine
Over 2 yd³ — call a local ready-mix plant

For 2 yards, you’d need 120 of the 60 lb bags or 90 of the 80 lb bags — that’s a full day’s work for two people mixing manually.

Pro Tips and Field Notes

Mix consistently: Always measure water accurately per bag to maintain uniform strength.
Batch close to the pour: Concrete begins setting in 30–60 minutes; don’t mix too far in advance.
Use clean water and tools: Contaminants affect setting and color.
Combine partial bags cautiously: Half-used bags can clump or absorb moisture.
Check expiration dates: Cement compounds degrade over time; use fresh stock.
Reinforce wisely: Add rebar, mesh, or fiber mix if your slab or footing will bear heavy loads.
Temperature and humidity matter: In hot weather, keep your mix shaded and cure with water for at least 3 days.

Concrete Bags Per Yard — Exact Conversions
Convert Yards to Bags
Convert Concrete Volume into Bags
Understanding Concrete Bag Coverage and Yield
Visit Concrete Calculator Max for all concrete mix calculators and estimation tools.

Conclusion

So, how many bags of concrete are there in a yard?

In simple terms:

40 lb bags → 90 per yard
50 lb bags → 72 per yard
60 lb bags → 60 per yard
80 lb bags → 45 per yard
20 kg bags → 82 per yard

That’s your quick reference for any concrete project — whether it’s a small patio, footing, or fence post base.

To eliminate guesswork, double-check your volume instantly with the Concrete Bags Calculator — it saves time, errors, and mid-pour panic every time.