Retaining WallCalcContact
PROJECT MATERIAL PLANNING

Retaining wall calculator UK

Estimate retaining wall materials in metric units with editable GBP prices, full-course block counts and clear material-order assumptions.

US & metric units
No account needed
Your wall
m

Measure along the wall alignment.

m

Block face only; exclude the cap.

rows

Use the embedment from your plans.

mm
mm
mm

Presets are generic examples. Check actual product coverage and packaging.

Cutting & breakage allowance
%
Schematic wall section showing caps, wall units, base aggregate and the drainage zone. Not to scale.1 mCapDrainage stoneBase aggregate1 buried courseSECTION VIEW · NOT TO SCALEWall run: 10 m
Dimensions and material zones follow your inputs. Confirm the construction detail with your wall supplier.
Updates as you type
YOUR MATERIAL ESTIMATEPlanning quantity
165wall units to order

150 net units + 15 for cuts and breakage.

28Cap stones
4.53Stone · m³
3Whole pallets*
MaterialQuantity
Wall units125 exposed + 25 buried + 15 allowance165 blocks
Cap stones25 net + 3 allowance28 caps
Leveling base aggregateVolume plus your stone allowance1.01 m³
Drainage & core-fill stoneRectangular backfill zone plus selected core fill3.51 m³
Drain pipe1 roll(s) at entered roll length11.22 m
Geotextile sheet allowanceOne rear face and bottom strip, plus overlap17.31 m²
Cap adhesiveCoverage and bead count you specified3 tubes
Materials at entered prices£1,083

GBP · Individual units and volumes; delivery, labor and tax are extra.

*Pallet packaging is editable. Costs use individual quantities. Material estimate only; verify products and site-specific design.

THE COMPLETE TAKEOFF

Quantities, prices & assumptions

10 m wall run · 10 m² exposed face
MaterialOrder quantityEntered unit priceLine total
Wall units125 exposed + 25 buried + 15 allowance165 blocks£2.75 / blocks£454
Cap stones25 net + 3 allowance28 caps£4.50 / caps£126
Leveling base aggregateVolume plus your stone allowance1.01 m³£78.48 / m³£80
Drainage & core-fill stoneRectangular backfill zone plus selected core fill3.51 m³£91.56 / m³£322
Drain pipe1 roll(s) at 50 ft; fittings excluded11.22 m£4.10 / m£46
Geotextile sheet allowanceOne rear face and bottom strip, plus overlap17.31 m²£1.94 / m²£34
Cap adhesiveCoverage and bead count you specified3 tubes£7.50 / tubes£23
DeliveryEntered allowance—£75
Labor10 m² exposed face£0.00 / m²£0
Modeled tax0% on materials + delivery—£0
Total example budgetReplace example prices with your quotes£1,158 GBP
1 buried course10% unit allowance10% stone allowance7.52 tonnes stone at entered density

Unit dimensions: 400 × 200 × 300 mm. 1 buried courses. Cutting allowance 10%. Stone allowance 10%. Supplier density 1.66 t/m³.

Material estimate only. Package rounding, design, permits, equipment, excavation and fittings are separate. Verify all inputs against actual products and approved plans.

retainingwallcalc.org · 2026

Plan quantities in metric units

Use metres for the wall dimensions and millimetres for blocks, caps and stone-zone depths. The output provides cubic metres and metric tonnes, with an editable density. GBP prices are entered by you from a local quote.

For mortared concrete blocks, use the dedicated CMU tool and distinguish the actual unit dimensions from the joint-inclusive module. This segmental-wall tool does not include mortar, concrete grout or reinforcement steel.

Separate the wall system from the takeoff

Concrete masonry, dry-stacked segmental units, gabion baskets and other systems have different components and design details. A block count cannot be treated as a gabion fill calculation or a foundation design.

This tool does not determine planning permission, building control requirements or compliance with a British standard. Use relevant local advice and the selected manufacturer’s details for the actual wall.

Check bulk bags and deliveries

Suppliers may sell aggregate in bulk bags by weight or loose loads by volume. A bag labeled with a weight is not automatically a fixed cubic-metre volume. Use its stated material density or the supplier’s conversion to check the order.

The takeoff reports geometric quantities plus the allowance you enter. Ask the supplier to round them to available package sizes and include delivery or unloading charges in the quote.

References and scope

Arithmetic and worked examples are explained on our methodology page. These manufacturer references provide product-specific context, not approval of a generic wall. Accessed October 1, 2026.

Read the estimating and engineering limits, or send a correction.

KEEP PLANNING

Related tools & guides

01

Cinder block quantity calculator

Estimate concrete masonry units using actual dimensions plus an entered mortar joint. Count courses and waste without implying a structural wall design.

02

Methodology and formulas

Inspect the formulas behind our wall, gravel, cap, pipe, fabric, reinforcement and cost quantities, including rounding and exact unit conversions.

03

calculator

Estimate retaining wall blocks, gravel, caps, pipe and project costs. Includes buried courses, waste allowance, metric units and a printable material list.