Aggregate Quantity Calculator

Calculate the coarse aggregate (jelly / metal) needed for a concrete job in cubic feet, cubic metres and tonnes.

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Inputs

Formula

  • Dry volume = wet volume × 1.54
  • Aggregate = dry volume × aggregate part ÷ total parts
  • Weight = volume × 1500 kg/m³

Coarse aggregate is the largest share of a concrete mix — three parts out of 5.5 in M20. Take the wet concrete volume, add 54% for the dry state, and split it by the mix ratio. Crushed 20 mm stone weighs about 1,500 kg per cubic metre loose.

Step-by-step calculation

  1. 1

    Dry volume

    wet × 1.54

    15.4 m³

  2. 2

    Aggregate share

    dry × 3/5.5

    8.4 m³

  3. 3

    Weight

    volume × 1500

    12,600 kg

Worked example

  1. 110 m³ of M20 → dry volume 15.4 m³.
  2. 2Aggregate = 15.4 × 3/5.5 = 8.4 m³.
  3. 3Weight = 8.4 × 1500 = 12.6 tonnes.

Tips

  • Use 20 mm aggregate for slabs and beams, 10–12 mm for thin sections and heavy reinforcement.
  • Wash dusty aggregate — silt on the stone weakens the bond with cement.

Frequently asked questions

What is jelly or metal?

Local names for crushed coarse aggregate. 20 mm is the standard size for house construction.

How many cubic feet in a tonne of aggregate?

About 23.5 cu ft, since a cubic metre weighs roughly 1,500 kg.

Does the grade change the aggregate quantity?

Yes. Richer mixes such as M25 use more cement and slightly less aggregate per cubic metre.

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