How many mixer loads in 1 cubic metre of concrete?

It depends on your mixer size. A full-bag Belle mixer (130L output) needs about 8 loads per m³. A half-bag mixer (90L output) needs about 12 loads. A mini mixer (60L output) needs about 17 loads, and hand mixing in a barrow (40L) takes around 25 batches per m³.

How many bags of cement do I need per cubic metre of concrete?

For a standard C20 general purpose mix (1:2:4 ratio by volume), you need approximately 6.5 bags of 25 kg cement per cubic metre. This is a general-purpose mix suitable for foundations, paths and floor slabs. Stronger mixes (C25, C30) require more cement per m³.

What is the difference between mixer drum size and output?

The drum capacity is the total volume of the mixer drum, but you cannot fill it completely — you need room for the materials to tumble and mix properly. Usable output is typically 65-75% of drum capacity. A 150-litre drum mixer produces about 90-100 litres of mixed concrete per load.

Is it cheaper to mix concrete on site or order ready-mix?

For small volumes (under 1 m³), site mixing is usually cheaper as ready-mix suppliers typically have a minimum order of 1-3 m³ with a premium for small loads. For volumes over 2-3 m³, ready-mix is often more cost-effective and saves significant labour time. The break-even point is typically around 1.5-2 m³.

How long does site mixing concrete take?

Each mixer load takes approximately 5-8 minutes of mixing time, but the total time per batch including loading materials and placing concrete is closer to 10-15 minutes. For 1 m³ using a full-bag mixer, allow approximately 2-3 hours total including breaks. It is physically demanding work.

Concrete Mixer Loads Converter — How Many Mixer Loads for My Concrete?

How We Calculate This

This calculator converts a total concrete volume (in m³) into the number of individual mixer loads based on your mixer type and its usable output capacity.

Mixer Output Capacities

Mini Mixer (90L drum): ~60 litres usable output per load
Half-Bag Mixer (130L drum): ~90 litres usable output per load
Full-Bag Mixer (180L drum): ~130 litres usable output per load
Barrow Mix (hand): ~40 litres per batch

Standard C20 Concrete Mix (1:2:4)

The materials are calculated using a standard C20 general purpose mix ratio of 1 part cement to 2 parts sharp sand to 4 parts coarse aggregate (20mm), by volume. Per cubic metre of concrete this requires approximately:

6.5 bags of 25 kg cement
0.45 m³ of sharp sand (~680 kg)
0.9 m³ of 20mm aggregate (~1,350 kg)

Time Estimates

Mixing time per load varies by mixer: mini mixers ~8 minutes, half-bag ~7 minutes, full-bag ~6 minutes, and barrow mixes ~5 minutes. These are mixing-only times — total time per batch including loading, pouring and cleaning will be longer.

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.

Concrete Mixer Loads Converter — How Many Mixer Loads Do I Need?