Retaining Wall Calculator
Plan your landscaping project with confidence. Calculate the number of blocks, amount of backfill, and total cost for your retaining wall.
Input Dimensions
Calculation Results
How to Use the Retaining Wall Calculator
Estimating materials for a retaining wall is vital for both cost control and structural safety. Start by entering the total length and height of the wall in meters.
Next, choose the type of blocks or stones you plan to use and enter their specific dimensions. If your wall requires a gravel backfill or a concrete footing, factor those in as well for a complete estimate. Enter the cost per block for a total price projection. Click "Calculate Now" to see the total number of blocks needed and the estimated project cost.
Pro Tips for a Strong Retaining Wall
Drainage is Vital
The most common cause of retaining wall failure is water pressure trapped behind the wall. Always include a perforated drainage pipe at the base and use clean gravel for backfilling.
Check for Permits
Many local building codes require a structural engineer's design and a permit for any retaining wall over 1 meter (approx. 3 feet) in height. Always check with your local authorities first.
Frequently Asked Questions
How deep should a retaining wall footing be?
A general rule is that the footing should be at least 150mm to 300mm deep, or 1/8th of the total wall height, whichever is greater, to ensure the wall doesn't shift or settle unevenly.
What is the best material for a retaining wall?
Interlocking concrete blocks are the most popular choice for DIY projects due to their ease of installation, built-in drainage features, and long-term durability in various weather conditions.
Do I need to use mortar for my retaining wall?
Many modern retaining wall systems are designed to be "dry-stacked," meaning they don't require mortar. Gravity and the specialized interlocking design are sufficient to hold the wall securely in place.