Concrete Calculator – Volume in Yards, M³ & Bags

This calculator multiplies your slab dimensions with Volume = Length × Width × Depth, converts between cubic meters and cubic yards (1 m³ = 1.308 yd³), and then prices the pour in cement bags. At the standard 1:2:4 mix you need roughly 6-7 × 50 kg bags of cement per cubic meter, plus 0.45 m³ of sand and 0.9 m³ of gravel. Worked example: a 6 × 4 m patio slab at 12 cm needs 2.88 m³ (3.77 yd³) - about 19 bags. Ready-mix trucks sell whole cubic meters, so order 3 m³, not 2.88, and always add 5-10% for spillage and uneven subgrade.

1. 1

   Measure the space

   Record the length, width and depth at the widest and longest points.

2. 2

   Enter the values

   Type the measurements into the calculator and select your units.

3. 3

   Apply the formula

   The tool computes Volume = Length × Width × Depth for your inputs instantly.

4. 4

   Add waste and order

   Review the total with a 5-10% margin and round up to whole units.

• Measuring in mixed units

• Forgetting the waste factor

• Ordering exact volume