How Much Concrete Can a Mixer Produce Per Day? Simple Math

Contractors ask us this before every slab: will one mixer finish the pour in a day, or do I need a bigger drum? The math is simple once you know three numbers. Concrete per batch, batches per hour, and real working hours. Let us work through it for the drum sizes in our concrete mixer range.

Step 1: concrete per batch

Mixer capacity is quoted by drum size, but the practical measure is bags of cement per batch. Our 240L, 250L and 280L mixers are half-bag machines. The 350L mixer takes three-fourth of a bag. The 500L Kirloskar diesel mixer takes a full bag.

Now convert bags to concrete. A standard 1:2:4 nominal mix needs roughly 6.5 bags of cement per cubic metre. So:

• One bag of cement gives roughly 0.15 cubic metre of mixed concrete
• Half a bag gives roughly 0.07 to 0.08 cubic metre
• Three-fourth of a bag gives roughly 0.11 cubic metre

Step 2: batches per hour

A batch cycle is loading, mixing and discharge. On a well-run site with two helpers feeding the drum, count roughly:

1. Loading cement, sand, aggregate and water: 1.5 to 2 minutes
2. Mixing: 2 to 3 minutes
3. Discharge into pans or a wheelbarrow: about 1 minute

That is about 5 to 6 minutes per batch, so 10 to 12 batches per hour on paper. Plan for 8 to 10 batches per hour in practice, because material handling never runs perfectly.

Step 3: real working hours

An 8-hour shift never gives 8 hours of mixing. Setup, shifting material closer to the drum, tea breaks and cleaning eat into it. Count on 6 hours of actual mixing, which means roughly 50 to 60 batches in a day.

Putting it together

Worked example. A typical 100 square metre house slab at 125 mm thickness needs about 12.5 cubic metres of concrete. A half-bag mixer would take close to three days. The 500L one-bag machine, starting around ₹1,30,000, gets you through in a day and a half. That is why slab contractors almost always run the big drum.

What slows output on real sites

• Material distance. If sand and aggregate sit 20 metres from the drum, your cycle time doubles. Stack material next to the mixer.
• Too few helpers. One person cannot load and shift concrete at the same time. Budget labour to match the machine.
• Power interruptions. Electric mixers stop when supply does. See our comparison of diesel vs electric concrete mixers if your site power is unreliable.
• Long discharge paths. Pouring a first-floor slab by pan and rope is far slower than a ground-level pour.

Planning a pour with these numbers

Work backwards from the concrete you need. Measure your slab volume, divide by the daily output of the mixer you own, and you have your pour schedule. If the answer is more than one day for a structural slab, think again. Slabs should ideally be poured continuously, so either hire a second mixer, upgrade to the one-bag machine, or split the slab with a properly planned construction joint. Also order cement, sand and aggregate for the full day before you start. A mixer standing idle while someone fetches two more bags of cement is the most expensive machine on site.

Still deciding between drum sizes? Our guides on which mixer size you need and half-bag vs full-bag mixers go deeper. Or call HMS in Bengaluru and tell us your slab area. We will do this math with you before you spend a rupee.