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Brick & block estimator

Estimate one rectangular nonstructural wall, one layer of units thick. Enter your own brick or block dimensions and joints.

Turn on JavaScript to use these fields. No example result is shown. The explanation below shows the calculation. You can also browse All tools.

Your wall and units

Wall length (m)0,01 to 30 m, up to two decimal places.

Wall height (m)0,01 to 10 m, up to two decimal places.

Unit face length, horizontal (mm)50 to 1 000 whole mm. Enter your brick or block's horizontal face.

Unit face height, vertical (mm)30 to 500 whole mm. The face orientation stays as entered.

Unit depth through the wall (mm)40 to 500 whole mm. Used for theoretical mortar only.

Head and bed joint thickness (mm)0 to 30 whole mm. Enter 0 for no wet joints in this model.

Extra unit allowance (%)Optional, 0% to 30%. Blank means no extra unit allowance; this doesn't add mortar losses.

Usable mixed mortar per bag (L)Optional, 0,01 to 200 L from your product label. No yield is assumed.

Door and window openings

Optional, up to six rectangles wholly inside this wall. We subtract their areas, but can't check their positions or overlap.

Your wall quantitiesFill in the details

Enter your wall, unit dimensions and joint thickness. No product dimensions are assumed.

Your wall, openings and product yield stay only on this page. Reloading or leaving clears them.

How it's worked out

We subtract the areas of your rectangular openings from the wall. Each unit's face length and height, each plus your joint thickness, form its nominal area. We apply your unit allowance to the exact area ratio, then round up once to whole units.

The same area estimate applies when valid face length and height are swapped. Unit depth affects theoretical mortar, not the count. We don't model courses, cuts, corners, cavity walls or multiple layers.

Theoretical wet mortar is net area times unit depth times the fraction occupied by uniform head and bed joints. It assumes joints through the full depth, excludes hollow-core filling and is a geometric approximation. Unit allowance adds no mortar losses. Litres are rounded up to 0,01 L; optional bags come from the unrounded volume and your product's usable litres per bag.

All measurements and product figures come from you. Confirm product instructions and actual site requirements. No strength, load-bearing suitability, reinforcement, foundations, lintels, building approval or material order is certified here.

Brick & block estimator

Your wall and units

Door and window openings

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