Bricks & Blocks Calculator

The number of bricks needed depends on wall area, brick size and bond pattern. Standard UK bricks measure 215 × 102.5 × 65 mm. With a 10 mm mortar joint, you need approximately 60 bricks per square metre for a half-brick wall (single skin) in stretcher bond. A full-brick (one-brick) wall, 215mm thick, uses about 120 per m². So a 4m × 2m wall of 8 m² takes 480 bricks as a single skin or 960 as a double skin, before wastage. Engineering bricks are slightly larger at 215×102.5×73mm and are used for footings and retaining walls because of their higher strength and lower water absorption.

This calculator takes your wall dimensions, subtracts openings (doors, windows) and applies the correct rate per square metre. It also adds a wastage allowance, typically 5% for straightforward walls and 10% if there is significant cutting (such as around window reveals or corners with Flemish bond). Enter the wall length, height and the size of any openings, choose the bond pattern and wall thickness, and the results show total bricks needed, bags of mortar (approximately 1 bag of cement per 35–40 bricks) and estimated cost. For large projects, order a sample panel first to confirm the brick choice and mortar colour.

Brick prices are quoted per thousand. Common stock bricks cost £400-£700 per 1,000, or 40-70p each. Engineering bricks (Class A or B) run £600-£1,200 per 1,000 and are high-strength, dense and weatherproof. Facing bricks, chosen for their appearance, cost £600-£1,500 per 1,000 in many styles, and reclaimed Victorian or Georgian bricks for conservation areas and period properties fetch £800-£3,000 per 1,000. Concrete blocks at £1.50-£3.00 each and 100mm thick are the cheaper choice for an inner skin. A cavity wall is built as an outer skin of facing brick, an inner skin of concrete block and insulation in a 50-100mm cavity.

Mortar needs its own sum. Allow 0.7 m³ of mortar per 1,000 bricks with typical 10mm joints. One cubic metre of mortar takes 250kg of cement (5 × 25kg bags) and 1.25m³ of sand, and sand costs £40-£60 a tonne, with 1m³ weighing about 1.6 tonnes. The mix ratio depends on the job: 1:5 cement to sand for above-ground walls, 1:4 for chimneys and high-strength work, 1:3 for engineering brick footings, and 1:6 with plasticiser for general work. Solid-wall buildings from before the 1920s need lime mortar (NHL 3.5), which costs about 3× as much as cement mortar but lets the wall breathe.

Labour is usually the larger cost. A skilled bricklayer lays 400-600 bricks a day on a single-skin facing wall, and 300-400 a day on slower engineering-brick footings. Self-employed bricklayers in the UK charge £200-£350 a day depending on region. If you are laying yourself, an entry-level kit of trowel, spirit level, line and pins, plumb bob, string, mortar board, brick hammer and jointing tool costs £100-£200. The trade route is a 4-year apprenticeship at college to NVQ Level 2 or 3 on CITB-accredited courses, which gives some idea of how much technique is involved.

Rules apply once walls get tall or close to neighbours. A garden wall under 1m needs no permission, but planning permission is required above 1m next to a highway and above 2m elsewhere. Retaining walls holding back more than 1.2m of soil need structural calculations and often Building Control approval. Extensions and structural openings fall under Building Regulations, with lintels and structural calculations required. Under the Party Wall Act 1996, working within 3m of a neighbour's foundations or attaching to a shared wall means notifying the neighbour 2 months in advance. Where solid walls are insulated, Building Regulations set a U-value target of 0.30 W/m²K.