Footing

Isolated footing concrete

LengthWidthDepthNo. of footingsnos

Concrete Volume

m³

Per footing: 0 m³
Cement: 0 bags
Sand: 0 m³
Aggregate: 0 m³

Mark

Quantitynos

How we got this

1
Volume of one footing
V₁ = L × W × D
= 0 × 0 × 0
= 0 m³
2
Total concrete
V = V₁ × No. of footings
= 0 × 0
= 0 m³
3
Dry volume of concrete
Dry volume = Wet volume × 1.54
= 0 × 1.54
= 0 m³
Dry ingredients bulk up; they lose ~54% volume once water is added and the mix is compacted.
4
Cement (M20 = 1 : 1.5 : 3, sum of ratio 5.5)
Cement volume = Dry volume × 1 / 5.5 ; bags = volume / 0.0347
= 0 × 1/5.5 = 0 m³ ÷ 0.0347
= 0 bags (0 kg)
One 50 kg bag of cement occupies 0.0347 m³ (density 1440 kg/m³).
5
Sand (fine aggregate)
Sand = Dry volume × 1.5 / 5.5
= 0 × 1.5/5.5
= 0 m³
6
Coarse aggregate (20 mm)
Aggregate = Dry volume × 3 / 5.5
= 0 × 3/5.5
= 0 m³
7
Water (for W/C 0.5)
Water = Cement weight × 0.50
= 0 × 0.50
= 0 litres

The theory behind it

Method used: Rankine's earth-pressure theory for depth of foundation, with IS 456 limit-state bearing check

An isolated footing is a rectangular pad: volume = L × W × D per footing, multiplied by the number of identical footings. The material split then follows the standard M20 dry-volume method.

Assumptions used

•M20 grade, nominal mix 1 : 1.5 : 3 (cement : sand : aggregate).
•Dry-volume factor 1.54 on wet concrete volume.
•Cement bag = 50 kg = 0.0347 m³ (bulk density 1440 kg/m³).
•Water-cement ratio 0.50; adjust for admixtures or site moisture.
•No deduction for embedded reinforcement (usually < 1.5% of volume).
•For reinforcement, use the Steel Quantity calculator or the full Bar Bending Schedule (BBS).
•Rectangular (not sloped or stepped) footing; for a sloped pad, use the mean depth.
•PCC levelling course below is measured separately.

Codes & references

IS 456:2000 — Plain and Reinforced Concrete, Code of Practice
IS 10262:2019 — Concrete Mix Proportioning
HPR QS Master Guide, Part 2 — Concrete quantities

History

Estimates for guidance only. Confirm quantities with your site engineer.