Kenya House Construction
Cost Calculator
Accurate estimates based on current 2026 Kenyan market rates
Location & Property Type
Mafundi Calculator
Material Quantification
Module
Calculate individual building elements using standard Kenyan construction practices. Full formula display, editable assumptions, cost estimates and PDF report generation.
12
Modules
⚙ Global Settings — applied to all modules
Blinding Concrete
Thin concrete layer beneath strip footings — Mix Ratio 1:3:6
Wet Volume = Perimeter × Width × Thickness
Dry Volume = Wet Volume × 1.54 (voids factor)
Cement Bags = (Dry Vol × 1 / (1+3+6)) / 0.035 m³ per bag
Sand = (Dry Vol × 3 / 10) × 1.6 t/m³
Ballast = (Dry Vol × 6 / 10) × 1.65 t/m³
Dry Volume = Wet Volume × 1.54 (voids factor)
Cement Bags = (Dry Vol × 1 / (1+3+6)) / 0.035 m³ per bag
Sand = (Dry Vol × 3 / 10) × 1.6 t/m³
Ballast = (Dry Vol × 6 / 10) × 1.65 t/m³
📊 Blinding Concrete Results
Mix 1:3:6
📐 Volumes
Wet Volume
—
m³
Dry Volume (×1.54)
—
m³
🏗 Materials Required
Cement (50 kg bags)
—
bags
Sand
—
tonnes
Ballast / Aggregate
—
tonnes
Wastage Applied
—
% on quantities
Calculation Steps
⚠ Verify lengths from approved drawings. Add 5–10% wastage for on-site losses. Consult a QS before procurement.
Strip Footing Concrete
Reinforced strip foundation — Mix Ratio 1:2:4
Wet Volume = Length × Width × Thickness
Dry Volume = Wet Volume × 1.54
Cement Bags = (Dry Vol / (1+2+4)) × 1 × (1000/50) × density
Sand = (Dry Vol × 2 / 7) × 1.6 t/m³
Ballast = (Dry Vol × 4 / 7) × 1.65 t/m³
Dry Volume = Wet Volume × 1.54
Cement Bags = (Dry Vol / (1+2+4)) × 1 × (1000/50) × density
Sand = (Dry Vol × 2 / 7) × 1.6 t/m³
Ballast = (Dry Vol × 4 / 7) × 1.65 t/m³
📊 Strip Footing Results
Mix 1:2:4
📐 Volumes
Wet Volume
—
m³
Dry Volume (×1.54)
—
m³
🏗 Materials Required
Cement (50 kg bags)
—
bags
Sand
—
tonnes
Ballast / Aggregate
—
tonnes
Wastage Applied
—
%
Calculation Steps
⚠ Include rebar per structural engineer's specification. This covers concrete only.
Column Concrete
Rectangular reinforced concrete columns — enter one typical column size and quantity.
Wet Volume = Column Width × Column Length × Column Height × Number of Columns
Dry Volume = Wet Volume × 1.54 (voids factor)
Cement Bags = (Dry Vol × cement ratio / total ratio ÷ 0.035 m³ per bag)
Sand = Dry Vol × sand ratio / total ratio × 1.60 t/m³
Ballast = Dry Vol × aggregate ratio / total ratio × 1.65 t/m³
Dry Volume = Wet Volume × 1.54 (voids factor)
Cement Bags = (Dry Vol × cement ratio / total ratio ÷ 0.035 m³ per bag)
Sand = Dry Vol × sand ratio / total ratio × 1.60 t/m³
Ballast = Dry Vol × aggregate ratio / total ratio × 1.65 t/m³
📊 Column Concrete Results
Mix 1:2:4
📐 Volumes
Single Column Volume
—
m³
Total Wet Volume
—
m³
Dry Volume (×1.54)
—
m³
Concrete Class
—
ratio
🏗 Materials Required
Cement (50 kg bags)
—
bags
Sand
—
tonnes
Ballast / Aggregate
—
tonnes
Wastage Applied
—
% on quantities
Calculation Steps
⚠ This covers concrete only. Reinforcement steel, formwork, and column starter bars must be designed by a structural engineer.
Beam Concrete
Add Beam 1, Beam 2 and more beams. Each beam uses width, depth, length and concrete class.
Beam Wet Volume = Width × Depth × Length
Dry Volume = Wet Volume × 1.54
Total Materials = Sum of all beam volumes using selected concrete class
Dry Volume = Wet Volume × 1.54
Total Materials = Sum of all beam volumes using selected concrete class
📊 Beam Concrete Results
All beams
📐 Volumes
Total Wet Volume
—
m³
Dry Volume (×1.54)
—
m³
Concrete Class
—
ratio
Beam Count
—
beams
🏗 Materials Required
Cement (50 kg bags)
—
bags
Sand
—
tonnes
Ballast / Aggregate
—
tonnes
Wastage Applied
—
% on quantities
Calculation Steps
⚠ This covers concrete only. Beam reinforcement, stirrups, formwork and support conditions require structural design.
Column Base Concrete
Rectangular column bases/footing pads — length, width, depth, class and quantity.
Wet Volume = Base Length × Base Width × Base Depth × Number of Bases
Dry Volume = Wet Volume × 1.54
Cement / Sand / Ballast calculated from selected concrete class
Dry Volume = Wet Volume × 1.54
Cement / Sand / Ballast calculated from selected concrete class
📊 Column Base Results
Mix 1:2:4
📐 Volumes
Single Base Volume
—
m³
Total Wet Volume
—
m³
Dry Volume (×1.54)
—
m³
Concrete Class
—
ratio
🏗 Materials Required
Cement (50 kg bags)
—
bags
Sand
—
tonnes
Ballast / Aggregate
—
tonnes
Wastage Applied
—
% on quantities
Calculation Steps
⚠ Base size, depth and reinforcement must follow structural drawings and soil bearing capacity.
Foundation Stones
9-inch rubble stone foundation — linear measurement and stone count
Wall Area = Perimeter × Depth
Linear Metres = Wall Area ÷ Stone Thickness (0.20 m)
Linear Feet = Linear Metres × 3.281
Stone Count = (Perimeter × Depth) ÷ (stone L × stone H × thickness) × 1000
Linear Metres = Wall Area ÷ Stone Thickness (0.20 m)
Linear Feet = Linear Metres × 3.281
Stone Count = (Perimeter × Depth) ÷ (stone L × stone H × thickness) × 1000
📊 Foundation Stone Results
9-inch Rubble
📐 Dimensions
Total Wall Area
—
m²
Foundation Courses
—
courses
📏 Linear Measurement
Linear Metres
—
m
Linear Feet
—
ft
Stone Count
—
pieces (inc. wastage)
Wastage Applied
—
%
Calculation Steps
⚠ Stone dimensions assume standard 400×200×200 mm rubble. Adjust inputs for actual stone sizes.
Backfill Material
Fill volume and tonnage for floor build-up
Volume (m³) = Floor Area × Fill Depth
Tonnes = Volume × Material Density (t/m³)
Murram ≈ 1.8 t/m³ · Hardcore ≈ 1.9 t/m³ · Gravel ≈ 1.65 t/m³ · Selected Fill ≈ 1.75 t/m³
Tonnes = Volume × Material Density (t/m³)
Murram ≈ 1.8 t/m³ · Hardcore ≈ 1.9 t/m³ · Gravel ≈ 1.65 t/m³ · Selected Fill ≈ 1.75 t/m³
📊 Backfill Results
Murram
Volume
—
m³
Density Used
—
t/m³
Quantity (Tonnes)
—
tonnes (inc. wastage)
Lorry Loads (8t)
—
approx. lorry loads
Calculation Steps
⚠ Lorry capacities vary by vehicle. Confirm with supplier. Compact in 150 mm layers.
Floor Slab Concrete
Ground bearing slab — Mix Ratio 1:2:4
Wet Volume = Floor Area × Thickness
Dry Volume = Wet Volume × 1.54
Cement Bags = (Dry Vol × 1 / 7) ÷ 0.035 m³/bag
Sand = (Dry Vol × 2 / 7) × 1.6 t/m³
Ballast = (Dry Vol × 4 / 7) × 1.65 t/m³
Dry Volume = Wet Volume × 1.54
Cement Bags = (Dry Vol × 1 / 7) ÷ 0.035 m³/bag
Sand = (Dry Vol × 2 / 7) × 1.6 t/m³
Ballast = (Dry Vol × 4 / 7) × 1.65 t/m³
📊 Floor Slab Results
Mix 1:2:4
📐 Volumes
Wet Volume
—
m³
Dry Volume (×1.54)
—
m³
🏗 Materials Required
Cement (50 kg bags)
—
bags
Sand
—
tonnes
Ballast / Aggregate
—
tonnes
Wastage Applied
—
%
Calculation Steps
⚠ Include BRC mesh per structural engineer. This calc covers concrete only.
Machine Cut / Ndarugo Stones
Net wall area minus openings — 400 × 200 mm stones
Gross Wall Area = Perimeter × Height
Openings Area = Window Area + Door Area
Net Wall Area = Gross − Openings
Single Stone Area = 0.40 × 0.20 = 0.08 m²
Stone Count = Net Area ÷ 0.08 × (1 + wastage%)
Openings Area = Window Area + Door Area
Net Wall Area = Gross − Openings
Single Stone Area = 0.40 × 0.20 = 0.08 m²
Stone Count = Net Area ÷ 0.08 × (1 + wastage%)
📊 Walling Stone Results
Machine Cut
📐 Wall Areas
Gross Wall Area
—
m²
Openings Area
—
m²
Net Wall Area
—
m²
Single Stone Area
—
m²
🧱 Stone Count
Stones (before wastage)
—
pieces
Wastage Stones
—
pieces
Total Stones Required
—
pieces
Wastage Applied
—
%
Calculation Steps
⚠ Mortar and ties calculated separately. Includes perimeter walls only — add internal partition walls if required.
Roofing Sheets Calculator
Pitched roof area, sheet count, ridge caps — multiple sheet types
Slope Factor = 1 / cos(pitch°)
Roof Area = Floor Area × Slope Factor × 1.1 (overhang)
Effective Cover Width = sheet width − overlap
Sheets (length) = Rafter Length ÷ Effective Sheet Length
Sheets (width) = Roof Width ÷ Effective Cover Width
Total Sheets = Sheets(L) × Sheets(W) × (1 + wastage%)
Roof Area = Floor Area × Slope Factor × 1.1 (overhang)
Effective Cover Width = sheet width − overlap
Sheets (length) = Rafter Length ÷ Effective Sheet Length
Sheets (width) = Roof Width ÷ Effective Cover Width
Total Sheets = Sheets(L) × Sheets(W) × (1 + wastage%)
📊 Roofing Results
Box Profile
📐 Roof Geometry
Slope Factor
—
multiplier
Actual Roof Area
—
m² (inc. overhang)
🏠 Sheet Count
Sheets Required
—
sheets (inc. wastage)
Ridge Caps
—
pieces
Eff. Cover Width
—
m per sheet
Sheet Length
—
m standard
Calculation Steps
⚠ Ridge cap count based on 2 m caps at 150 mm overlap. Adjust for hip ridges and valleys. Hip sheets calculated separately.
Tiles Calculator
Floor or wall tiling estimation with wastage calculation
Total Area = Length × Width
Tile Coverage = Tile Length × Tile Width
Tiles Required = Area ÷ Tile Coverage × (1 + Wastage%)
Boxes Required = Tiles Required ÷ Tiles per Box
Tile Coverage = Tile Length × Tile Width
Tiles Required = Area ÷ Tile Coverage × (1 + Wastage%)
Boxes Required = Tiles Required ÷ Tiles per Box
📊 Tiles Results
Floor Tiles
📐 Area & Coverage
Total Area
—
m²
Tile Coverage
—
m² per tile
🟦 Quantity Required
Tiles Required
—
pieces (inc. wastage)
Boxes Required
—
boxes
Wastage Applied
—
%
Calculation Steps
⚠ Wastage accounts for cutting, fitting, and future repairs. Add extra 5% for intricate patterns or diagonal layouts.
Paint Calculator
Wall painting estimation with coats and coverage rate
Total Paintable Area = Wall Length + Wall Width + Height × 2
Or enter area directly = Total Wall Area (m²)
Total Area for Coats = Paintable Area × Number of Coats
Litres Required = Total Area ÷ Coverage Rate (L/m²)
Tins Required = Litres ÷ Tin Size
Or enter area directly = Total Wall Area (m²)
Total Area for Coats = Paintable Area × Number of Coats
Litres Required = Total Area ÷ Coverage Rate (L/m²)
Tins Required = Litres ÷ Tin Size
📊 Paint Results
2 Coats
📐 Wall Area
Gross Wall Area
—
m²
Openings Deducted
—
m²
Net Paintable Area
—
m²
🎨 Paint Requirements
Total Area (coats)
—
m²
Litres Required
—
L (inc. wastage)
Number of Tins
—
tins
Calculation Steps
⚠ Coverage rates vary by paint type. Emulsion: 10–12 m²/L, Gloss: 8–10 m²/L, Textured: 6–8 m²/L. Add 10% for porous surfaces.