How Many Bags of Concrete for a 6x8 Patio? (2026 Guide)
A 6x8 ft (48 sq ft) patio slab poured 4 in thick needs about 16 cu ft of concrete — 27 bags of 80-lb mix or 36 bags of 60-lb mix; at 3.5 in, about 24 bags of 80-lb.
How many bags for a 6x8 patio, by thickness
A 6x8 ft patio is 48 sq ft of surface area; thickness decides the volume. One 80-lb bag yields about 0.6 cu ft of mixed concrete and one 60-lb bag about 0.45 cu ft, so divide the volume by those figures and round up to the nearest full bag — a short bag means a skimpy pour.
| Slab thickness | Concrete needed | 80-lb bags | 60-lb bags |
|---|---|---|---|
| 3.5 in | 14 cu ft | 24 bags | 32 bags |
| 4 in | 16 cu ft | 27 bags | 36 bags |
| 5 in | 20 cu ft | 34 bags | 45 bags |
| 6 in | 24 cu ft | 40 bags | 54 bags |
The 4 in row is the practical default for a patio that carries foot traffic and a small table; 3.5 in is fine only where the ground is firm and use is light. Choose 5–6 in when the slab must hold something heavier than people and furniture, and always confirm a heavier pad against what you plan to set on it.
Worked example: a 6x8 ft patio, 4 in thick
Four inches is the standard pour for a backyard patio, so run that case once in full. Thickness in feet first: 4 in ÷ 12 = 0.333 ft. Volume is then 48 sq ft × 0.333 ft = 16 cu ft. With 80-lb bags: 16 ÷ 0.6 ≈ 26.7 → round up to 27 bags. With 60-lb bags: 16 ÷ 0.45 ≈ 35.6 → round up to 36 bags. The whole pour is only about 0.6 cu yd, which is why bags beat a ready-mix truck at this size.
Pouring a 6x8 patio that lasts
- Compact a 2–4 in gravel base — tamp it level first; a soft, uneven base is the main reason small patios crack and settle.
- Set and brace the forms, and slope the slab — square up the corners and pitch the finished surface about 1/4 in per ft away from the house so rain drains off instead of pooling at the door.
- Pour it in one go — 27 bags is about a morning with one helper mixing while the other places and screeds. A 6x8 ft slab is small enough to pour as a single piece; if you want a predictable crack line, tool one control joint down the center as the surface sets.
- Screed, then float — strike off along the forms with a straight 2x4, then bull-float once the water sheen disappears so the surface stays flat and pleasant to walk on.
- Cure with water — mist the patio and cover it with plastic for at least 3–5 days; keep it damp and stay off it for 24–48 hours so it gains strength instead of drying out.
Bigger or smaller than 6x8 ft?
The same math scales in both directions. A 4x4 ft pad takes about a third of this volume, and a 4x8 ft slab is the next size down — follow those sizes to how many bags of concrete for a 4x4 slab and how many bags of concrete for a 4x8 slab. If you only know your footprint, start from surface area with how many bags of concrete per square foot. For anything much larger than this, it's worth checking delivery prices — a ready-mix truck becomes practical once a pour passes about 1 cu yd.
FAQ
How many bags of concrete for a 6x8 patio at 4 in?
A 6x8 ft patio is 48 sq ft, so at 4 in thick it needs about 16 cu ft of concrete: 16 ÷ 0.6 ≈ 26.7, rounded up to 27 bags of 80-lb mix — or 16 ÷ 0.45 ≈ 35.6, rounded up to 36 bags of 60-lb mix.
How thick should a 6x8 ft patio slab be?
For a patio that only carries foot traffic and a small table, 3.5–4 in is the normal range: 3.5 in (about 24 bags of 80-lb mix) is light but serviceable, while 4 in (about 27 bags of 80-lb mix) is the safer default over soft ground. Pour 5 in or more only when the slab must support concentrated weight such as a hot tub.
Bags or a ready-mix truck for a 6x8 patio?
Bags. A 6x8 ft patio at 4 in is only about 0.6 cu yd (16 cu ft) — still under a typical 1 cu yd truck minimum, so ready-mix adds a short-load fee and leaves you with spare concrete. Stick with 80-lb or 60-lb bags for a 48 sq ft patio and consider a truck only once the job exceeds about 1 cu yd.
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