1. FORMULA USED FOR ESTIMATING
Earthworks
Excavation (m3
) = Height x Width x Length
Actual Backfill (m3
) = 1.25 x Theoretical Backfill
Theoretical Backfill (m3
) = VExcavation – VFooting – VGravel Bedding
Slab / Soil Poisoning (m2
) = Area of Building (Length x Width)
Grading (m2
) = Area of Column Footing (Length x Width)
Concrete Works
Volume of Footing (m3
) = Length x Width x Thickness x 1.1 (Height)
Volume of Column (m3
) = Length x Width x Height x 1.05
Volume of Stairs (m3
) = Length x Width x Height x 1.05
Volume of Slab (m3
) = Length x Width x Thickness x 1.05
Volume of Beam (m3
) = Base x Height x Length x 1.05
Number of Class “B” Cement Bags (Qty) = VConcrete x 7.5 bags/m3
Number of Sand (m3
) = VConcrete x 0.5 m3
/m3
Number of Gravel (m3
) = VConcrete x 1 m3
/m3
2. Formworks
Perimeter for Column (m) = (2 x Length) + (2 x Width)
Perimeter for Beam (m) = (2 x Base) + (2 x Height)
Perimeter for Slab (m) = (2 x Length) + (2 x Width)
Lateral Area for Column (m2
) = Perimeter x Height
Lateral Area for Beam (m2
) = Perimeter x Span
Lateral Area for Slab (m2
) = Perimeter x Thickness
Vertical Support for Column (Lumber Size: 2” x 3”) = Height x (7 Bd Ft/m)
Horizontal Support for Column (Lumber Size: 2” x 2”) = Height x (21 Bd Ft/m)
Diagonal/Brace Support for Column (Lumber Size: 2” x 2”) = Height x (11.7 Bd Ft/m)
Vertical Support for Beam (Lumber Size: 2” x 3”) = Height x (6 Bd Ft/m)
Horizontal Support for Beam (Lumber Size: 2” x 2”) = Height x (4.7 Bd Ft/m)
Number of Board Feet / Vertical Support for Slab (Lumber Size: 2” x 3”) = Lateral Area x (9.1
Bd Ft/m2
)
Number of Plywood (Qty) = Lateral Area / (2.88 m3
/ plywood)
Number of Board Feet (Qty) = Number of Plywood x (22 board feet/plywood)
Number of Form Oil (L) = Lateral Area / (25 m3
/ L)
Number of Nails (kg) = Lateral Area x (0.4 kg/m2
)
Tileworks
Total Number of Tiles along its Length (Qty) = (Length – Wall Thickness)/0.6
Total Number of Tiles along its Width (Qty) = (Width – Wall Thickness)/0.6
Total Number of Tiles (Qty) = (Total Number of Tiles along its Length x Total Number of
Tiles along its Width) – Number of Tiles occupied by stairs
Area (m2
) = Length x Width
Number of Class “A” Cement Bags for Mortar Mix (Qty) = Area x (0.45 bags/m2
)
Number of Sand (m3
) = Area x (0.025 m3
/m2
)
3. REINFORCE STEEL WORKS
Total Length = Height - concrete cover (2xdiameter)+ main bar end hooks
Total Length of all (m) = Total length x Quantity x No. of Main Bars
No. of 6 m Steel bars = Total Length of all / Length of the steel bar x allowance for splicer
Total Length Tie A B= Column Dimension -(2 x Concrete cover) x No. of sides + ( floor x 6 x
diameter)/1000
Total No of Ties = Total Length / Length of Bar / diamter of ties
No. of Lateral Ties In Columns = 2 + No of ties
Total Length of Lateral Ties = Total Length of Ties x Quantity x No. of Lateral Ties in Columns
Tie Wires (kg) = Quatity x (No of Ties + No of Main bars) x No of Later Ties in Columns x 0.4
/53
Total Length of Web Bars = Span x No. of Web Bars
Total Length of Support = Span x top support + 0.25 + 0.25 + Span x Bot support + 0.25
Total Length of Midspan = Span / 2 x Midspan top support + span/2 x Midspan bottom support
Gross Area = Length x Height x Quantity
Net Area = Gross Area - Opening
Vertical and Horizontal( pcs ) = Net Area x Bars in M per Sq.m / 6
Parallel Length and Width = W or L - 2(concrete cover)+ diameter
Total Cut Bars = pcs x 2 x quantity
Masonry Works
Gross Area (m2
) = Length x Height
Net Area (m2
) = Gross Area – Opening
Number of CHB (Qty) = Net Area x (12.5 CHB/m2
)
4. Interior (CHB = 4” thick):
Number of Class “A” Cement Bags for Mortar Fillers and Binders (Qty) = Number of CHB x
(0.0411 bags/CHB)
Number of Sand for Mortar Fillers and Binders (m3
) = Net Area x (0.0022 m3
/m2
)
Number of Class “A” Cement Bags for Plaster (Qty) = Net Area x (0.0411 bags/m2
)
Number of Sand for Plaster (m3
) = Net Area x (0.0022 m3
/m2
)
Exterior (CHB = 6” thick):
Number of Class “A” Cement Bags for Mortar Fillers and Binders (Qty) = Number of CHB x
(0.0982 bags/CHB)
Number of Sand for Mortar Fillers and Binders (m3
) = Net Area x (0.053 m3
/m2
)
Number of Class “A” Cement Bags for Plaster (Qty) = Net Area x (0.0982 bags/m2
)
Number of Sand for Plaster (m3
) = Net Area x (0.01 m3
/m2
)
Number of Class “A” Cement Bags for Plaster in Beams and Columns (Qty) = Area x (0.082
bags/m3
)
Number of Sand for Plaster (m3
) = Area x (0.009 m3
/m2
)
Painting Works
Gross Area (m2
) = Length x Height
5. Net Area (m2
) = Gross Area – Opening
Number of Boysen Epoxy Primer (L) = Net Area x (20 m2
/4L)
Boysen Masonry Putty (L) = Net Area x (10m2
/4L)
Boysen Permacoat Latex (2 coats) (L) = (Net Area x 2) x (25m2
/4L)