How many bags of concrete?
Bags are sold by weight. Coverage is sold by mixed volume. Always read the yield on the data sheet for the exact product on your pallet — high-early or fast-set mixes can differ.
Get project volume from measurements or from how much concrete do I need, then apply the table for your market.
US bag yields (40, 60, 80 lb)
QUIKRETE Concrete Mix No. 1101 (and matching Sakrete high-strength yields) as published:
| Bag | Approx. yield | Bags per yd³ (no waste) |
|---|---|---|
| 40 lb | 0.30 cu ft | 90 |
| 60 lb | 0.45 cu ft | 60 |
| 80 lb | 0.60 cu ft | 45 |
Those per-yard counts are bare maths. Add waste, then round up so you are not short mid-pour.
UK bag yields (20 kg and 25 kg)
Blue Circle Multi-Purpose Concrete states one 20 kg bag typically produces around 0.01 m³ of fresh concrete — about 100 bags per cubic metre before waste. Hanson’s multipurpose MaxiPack20 lists about 0.009 m³, which needs closer to 111 bags/m³. Prefer the number printed on the bags you actually buy. 25 kg general-purpose bags are less consistent across brands; if the sack does not state yield, ask the merchant or assume roughly 0.011–0.012 m³ and verify on site with a trial mix.
Example: US AC unit pad
Worked example (US)
Pad 3 ft × 3 ft × 4 in. Volume = 3 × 3 × (4/12) = 3.0 cu ft. With 10% waste → 3.3 cu ft.
80 lb bags at 0.60 cu ft: 3.3 ÷ 0.60 = 5.5 → buy 6 bags. 60 lb bags at 0.45: 3.3 ÷ 0.45 = 7.3 → 8 bags. 40 lb at 0.30: 11 → 11 bags.
Answer: Six 80 lb bags (or eight 60 lb / eleven 40 lb) for this small pad including 10% waste.
Example: UK short path
Worked example (UK)
Path 4 m × 0.9 m × 75 mm = 0.27 m³. +10% → 0.297 m³. At 0.01 m³ per 20 kg Blue Circle bag: 29.7 → buy 30 bags. If your merchant’s 20 kg Hanson-type bag yields 0.009 m³: 0.297 ÷ 0.009 = 33 → 33 bags.
Answer: Roughly 30–33 bags of 20 kg multipurpose for 0.3 m³ including waste — confirm yield on the pallet.
Which bag size to buy
- Match the mixer. An 80 lb bag needs roughly a cubic foot of mixer space per QUIKRETE’s notes; oversized loads leave dry pockets.
- Plan water. Follow the bag’s water range; soup-thin mix wastes strength.
- Stop bagging huge slabs. Past ~0.5 yd³ / ~0.4 m³, ready-mix usually wins on time and consistency — see the volume guide for when to switch.
- Postcrete is not slab mix. Fast-set post products list bags per hole size, not m³ yield for paths.
Enter your dimensions in the Concrete Calculator to get bag counts alongside volume, then adjust if your brand’s yield differs from the defaults.
Mixing and staging
Stage bags under cover beside the mixer. Open one bag at a time; cement left in torn sacks sets with overnight dew. For QUIKRETE’s 80 lb mix, start near the lower water amount on the data sheet and add sparingly — a soup mix is easy to place and weak when cured.
On a two-person crew, one mixes while one places. On a solo shed pad, mix half-bags if the barrow trip is long so you are not racing a stiffening heap. Count empty bags as you go against the shopping list; it is the simplest check that you have not under-bought.
If the maths says 44 bags of 80 lb for a yard-scale pour, stop and price ready-mix. Bag economics collapse once you add mixer hire, time and the risk of a cold joint between batches. Volume first (how much concrete), bags second, truck when the bag wall looks ridiculous.
Frequently Asked Questions
How many 80 lb bags of concrete make a yard?
About 45 bags. One cubic yard is 27 cu ft; QUIKRETE lists 0.60 cu ft per 80 lb bag, so 27 ÷ 0.60 = 45 before waste.
How many 60 lb bags per cubic yard?
About 60 bags at 0.45 cu ft yield (27 ÷ 0.45). Add waste on top and round up.
How many 20 kg bags per cubic metre?
About 100 bags if each makes 0.01 m³ (Blue Circle multipurpose figure), before waste. Always check the yield on your brand.
Should I buy 40 lb or 80 lb bags?
80 lb bags cover more volume per bag and usually cost less per cubic foot, but they are harder to lift. 40 lb bags suit tight access and smaller people; you will carry more bags for the same pour.
Get local quotes
For pours past a few dozen bags, compare mini-mix instead.
USA: Angi / HomeAdvisor UK: CheckatradeSources
- QUIKRETE Concrete Mix No. 1101 data sheet — Yields: 40 lb 0.30 ft³; 60 lb 0.45 ft³; 80 lb 0.60 ft³.
- Sakrete High-Strength Concrete Mix — Confirms matching 0.30 / 0.45 / 0.60 ft³ yields on common US bag sizes.
- Blue Circle Multi-Purpose Concrete — 20 kg bag ≈ 0.01 m³ fresh concrete.
- Hanson Multipurpose Concrete TDS — MaxiPack20 ≈ 0.009 m³ — brands differ; read your bag.
When you are ready to estimate materials or cost for your project, open the Concrete Calculator and enter your measurements.