Foam-Block Calculator
Calculate foam concrete blocks for house and bathhouse: piece count, volume in m³, mortar. Standard 600×300×200 size.
Total length of all load-bearing walls, m
Floor to ceiling, m
Matches block width, mm
Total openings area, m²
Standard 600 mm
Standard 200 mm
Matches wall thickness, mm
Calculation formula
S = L × H − S_openings V = S × t / 1000 N = ⌈V / V_block⌉
Block volume V_block = L × H × W / 10⁹ m³. For 600×300×200 mm that is 0.036 m³. Cement-sand mortar consumption when laying on mortar (not thin glue) is about 50 kg per 1 m³ of masonry.
About the foam-block calculator
The foam-block calculator estimates how many blocks you need for a house, bathhouse or garage. Enter the wall perimeter, height, thickness and total area of windows and doors — the formulas compute masonry volume, block count and mortar consumption.
The default size is the most common 600×300×200 mm format — a D500–D700 foam concrete block used for load-bearing walls of low-rise houses. You can change block dimensions to any size sold in your area.
Foam blocks are traditionally laid on cement-sand mortar, so the result includes about 50 kg of mortar per 1 m³ of masonry. All calculations run in your browser and are suitable for preliminary estimates and material procurement.
Advantages
Openings subtracted
Windows and doors are removed from total wall area
Any block size
Not only 600×300×200 — set your own format
Mortar consumption
See how much cement-sand mix the masonry needs
Frequently asked questions
How is a foam block different from an aerated (gas) block?
Foam blocks are cast from cement mortar with a foaming agent — pores are closed and the block resists water well. Aerated (autoclaved) concrete blocks are factory-cured in autoclaves, giving better geometry and higher strength but more water absorption.
Which density should I choose for a house?
For load-bearing walls of low-rise houses use D600–D700 — structural-thermal foam concrete. D500 is warmer but only suits single-storey or non-load-bearing walls. D400 and below is insulation, not for structural loads.
Do I need to reinforce foam-block masonry?
Yes — a reinforced ring beam under floor slabs and the wall plate is mandatory, plus mesh or 8 mm bars in a chase every 3–4 courses. This protects the walls from cracks during shrinkage and temperature movement.
Should foam blocks be laid on mortar or thin glue?
The classic method is a 10–15 mm cement-sand mortar joint, as used in this calculator. Thin-bed glue or polyurethane foam works only with category-1 blocks of perfect geometry, otherwise you get too many cold bridges.
How many 600×300×200 foam blocks fit in one cubic metre?
One 600×300×200 block has a volume of 0.036 m³, so about 27.7 blocks fit in 1 m³. The calculator always rounds up, so plan an extra 5–10% for cuts and breakage on top.
What reserve of foam blocks should I order?
Add 5–10% on top of the calculated count for breakage during unloading, cuts at openings and corners, and possible geometry defects. It is much better to keep some leftover than to halt the masonry waiting for one extra pallet.