Concrete & Ballast1m³ Ready-Mix (mixer truck)
C25 ready-mix concrete delivered by mixer truck, priced per cubic metre. Best for slabs over 0.5m³.
£165.00
£16.50 / 100L
Concrete Calculator — How Much Concrete Do I Need?
Enter your slab, footing or post-hole measurements in metres and get exact volumes, bag counts, costs and a ready-to-order material list.
01 — The Calculator
How much concrete does your garden need?
Pace out your plot and enter the measurements — the value engine prices every way to fill it, hippo bags, dumpy bags or handy sacks.
Enter dimensions to calculate.
Volume
0 litres
Cubic
0.00 m³
Area
0.0 m²
Est. weight
0.00 tonnes
Best price
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Enter your plot size below — we'll price the cheapest way to cover it.
10 cm
0102030 cm
Depth changes the volume a lot — 5cm mulch is normal, raised veg beds want 20cm+.
Not sure? See the depth guide belowJust-add-water bags — the easy option for posts, small pads and repairs.
The Catalogue
Your Materials Catalogue
Browse and customise your personal price list below. The default prices shown are indicative — useful as a starting point for budgeting, but your actual merchant prices will vary.
Why set your own prices?
When you update a product with your negotiated merchant price, every estimate and project board you create will automatically use your rate. Your quotes reflect what you actually pay, not a generic average — giving you more accurate margins and faster, more professional estimates.
How it works
- 1Click “Customise your own prices” and find the product below
- 2Enter your merchant price
- 3Save — stored on this device, and synced to your trade account when logged in
- 4Every project board and trade estimate now applies your saved price automatically
Your custom prices can be updated at any time as your supplier rates change. Logged-in trade users: your prices follow you across every device.
Custom prices flow into the calculator, project board and trade estimates automatically.
Hard Landscaping4 products
Concrete & BallastConcrete & Ballast850L Ballast Bag
All-in-one ballast for mixing your own concrete — just add cement and water.
£62.00
£7.29 / 100L
Concrete & Ballast25kg Concrete Bag (≈12.5L)
Just-add-water high-strength concrete for posts, small pads and repairs. ≈12.5L per bag.
£7.50
£60.00 / 100L
Concrete & Ballast25kg Cement Bag
General-purpose Portland cement for mixing your own concrete — about 13 bags per m³ with all-in ballast, just add water.
£6.75
£6.75 / m
Default prices are indicative only — confirm with your merchant before ordering.
Worked example — a shed base
- 1Shed base measures 2.4m × 1.8m, cast 100mm thick.
- 2Volume: 2.4 × 1.8 × 0.1 = 0.43m³ ≈ 430 litres of concrete.
- 3That's about 35 × 25kg bags of concrete mix at 12.5L per bag.
- 4Mixing from ballast instead? At a 1:5 mix that's one 850L bulk bag of ballast plus 4 × 25kg bags of cement.
Concrete depths and coverage guidance
- Shed and summerhouse bases: 75–100mm over a compacted hardcore sub-base.
- Driveways, garages and hot tubs: 100–150mm with reinforcement mesh.
- 1m³ of concrete weighs about 2.4 tonnes — plan barrow access before ordering.
- Over half a cubic metre, a delivered ready-mix load usually beats bags on price and effort.
Related calculators and guides
- Paving calculator — slabs over your new base
- Sand calculator — sharp sand for mortar and bedding
- Patio sub-base guide — what goes under the concrete
- Full depth guide for every material
Reviewed by the Garden Calculator editorial team.
Common questions
A 25kg bag of concrete mix yields about 12.5 litres, so 1m³ takes roughly 80 bags — at that scale a delivered ready-mix load usually wins on both price and your back. The calculator totals your volume in litres and m³ so you can compare bags against a delivered load before you commit.