How many bulk bags for 25 m2 of gravel?

A 25 m2 gravel area at 5 cm finished depth needs the bulk-bag count shown below when using 850 kg as the bag size. Supplier bulk bags vary, so replace 850 kg with the weight shown on your quote if it differs.

How to use this project example

This example uses a 25 m2 finished area at 5 cm depth. It estimates 1.25 m3 before applying density and allowance, so it is best used as a quantity check after the finished area and depth are decided.

• Measure inside the edging line or finished border, not the rough excavation area.
• Change the depth if the project needs more than decorative coverage.
• Split irregular shapes into sections and add the results together.

Ordering checks

The example uses 1.6 t/m3 density and 850 kg bags, giving 2.2 tonnes after allowance. Supplier bag weights, moisture, and delivery options can change the practical order.

• Confirm the supplier bulk-bag weight because 800 kg, 850 kg, and tonne bags are not interchangeable.
• Check delivery access and where the aggregate can be dropped.
• Keep a small allowance for edging losses, settlement, and topping up.

25 m2 bulk bag order gravel checks

Example inputs used

• Length: 5
• Width: 5
• Depth: 5
• Aggregate density: 1.6
• Bag size: 850

These are starting values for this example. Measure or confirm your own figures, then open them in the gravel calculator.

Assumptions and limits

• Uses 5 x 5 m as a simple 25 m2 square.
• Uses a typical decorative gravel density of 1.6 t/m3.
• Uses 850 kg as the bulk bag weight.
• Includes a 10% waste and settling allowance.

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