How we calculate
Where the coefficients come from, which norms, and how precise.
Principles
- We calculate by geometry, not by eye: quantities come from area, dimensions and format, not approximate tables.
- Where makers differ, we take the average value and say so.
- Usage norms follow GOST, EN and the technical sheets of KNAUF, Ceresit and others.
- Estimate only: exact use depends on the substrate and technique — always check the instructions on the pack.
Formula version 1.0 · Norms checked 08.2026
Sources by calculator
Ceiling tiles
- Geometry: area ÷ tile area
- Trim = perimeter + 5% for joints
Flooring
- Packs: area × (1 + reserve) ÷ pack area
- Roll width — by the room’s shorter side
Tile (walls / floor)
- EN 12004 / EN 12002 — adhesive classes C1/C2/S1/S2
- Adhesive use — by trowel notch (maker data sheets)
- Grout ≈ 0.5 kg/m²
Paint & enamel
- Coverage — by paint type (maker specs)
- EN 13300 — scrub-resistance classes
- Rough surface ×1.15
Thinner / solvent
- Compatibility and thinning % — by paint type
- Paint maker instructions
Wallpaper
- Strip cutting by height and pattern repeat
- Wallpaper paste ≈ 35 g/m²
Dry mixes
- Usage kg/m²/mm — by mix type
- Standard 25 kg bag
Suspended ceiling
- Suspended ceiling 600×600 (Armstrong type)
- Runners, wall angle and hangers — by the grid
Wall masonry
- GOST 530-2012 — brick sizes
- pcs/m³ = 1 / ((L+joint)(W+joint)(H+joint))
- Mortar grades M50–M150
Drywall
- KNAUF C111/C112, P113 — profile and fasteners
- Drywall sheet 2500×1200 = 3 m²
- EN 520 — standard / moisture / fire
Insulation
- ETICS — “rendered facade”
- Dowel norm — by building height
- Density and material — by application
Estimate only: exact use depends on the material, substrate and technique. Check the instructions on the pack. Where makers differ, we take the average value.