Adobe Brick Calculator

How it works

adobes per m² = 1 ÷ ((length + joint) × (height + joint)) · adobes = ⌈net area × per m²⌉ × (1 + allowance) · mortar = wall volume − adobe volume

Adobe walls are laid in running bond with the block’s width as the wall thickness, so each block covers its length plus one joint by its height plus one joint of wall face. Mud-mortar joints of 1.5–2.5 cm (⅝–1″) are usual; earthen building codes such as Peru’s Norma E.080 and ASTM E2392 call for walls at least 25–40 cm thick in seismic areas, with reinforcement and a bond beam. Sun-dried adobe weighs about 1,600 kg/m³, so a 40 × 20 × 10 cm block is close to 13 kg. Add 5% for broken blocks, more if you make them yourself.

Worked example

A 6 m wall 2.4 m high with 2 m² of openings has 12.4 m² of face. 40 × 20 × 10 cm adobes with 2 cm joints cover 0.42 × 0.12 m each, i.e. 19.84 per m², so the wall needs 247 adobes, or 260 with 5% extra. The 20 cm wall uses about 0.55 m³ of mud mortar (with 10% extra), and at 12.8 kg per adobe the total is 3.33 t.

Sources: ASTM E2392 — Standard Guide for Design of Earthen Wall Building Systems · Peru Norma E.080 — Diseño y construcción con tierra reforzada

Frequently asked questions