# HOW TO CALCULATE THE STEEL QUANTITY IN COLUMN FOOTING

The steel quantity in column footing can be calculated very quickly. Before calculating the steel read carefully the given footing drawing and note all the important points.

- Footing. (Length, Width, Thickness).
- The diameter of Footing reinforcement.
- A grade of reinforcement is going to use.
- The spacing of the reinforcement (c/c).
- Hook’s length (If needed).
- Concrete Covers of the Footing. (Top and Bottom).

**Example**

Suppose we have a Column Footing having a Length of 2 m, Width of 2 m and Thickness of 0.250 m. The main bars is 12 mm @ 150 c/c and Distribution bar is also 12 mm @ 150 c/c. The footing clear cover is 50 mm from the top and 75 mm from the bottom. Calculate the number of steel that is going to use in this Column Footing.

## Steel Quantity in Column Footing Formula

**Given Data:**

Length of the Footing = 2 m.

The width of the Footing = 2 m.

Thickness = 0.250 m

Main bar = 12 mm @ 150 c/c

Distribution bar = 12 mm @ 150 c/c

Clear cover = 50 mm from Top and Sides and 75 mm from Bottom.

**Solution:**

The first step is to calculate the number of bars which are going to use in the footing.

In the second step, we will calculate the cutting length of the bars and at last, we calculate the weight of the reinforcement bars.

**FOOTING MAIN BAR:**

No’s of Main bar = (Total distance – clear cover) / c/c + 1

No’s of Main bar = (2 m – (0.05+ 0.05) / 0.15 + 1

No’s of Main bar = 14 Bars.

Cutting Length of one Main Bar in Footing:

Length = {Total size – 2(Half diameter of the bar + Clear cover) + 2(Thickness of the slab –Bottom and Top clear cover – Half diameter of the bar)}.

Length = 2 m – 2 (0.006 + 0.05) + 2 (0.250 – 0.075 – 0.05 – 0.006).

Length = 1.676 m.

Total length = Length of one bar x No’s of bars.

Total length = 1.676 x 14.

Total length = 23.464 m.

Weight of the main bar:

Weight = D^2/ 162.2 x Length.

Total Weight = D^2 /162.2 x 23.464 m.

Total Weight = 20.84 kg.

**FOOTING DISTRIBUTION BAR:**

No’s of Distribution bar = (Total distance – clear cover) / c/c + 1

No’s of Distribution bar = (2 m – (0.05+ 0.05) / 0.15 + 1

No’s of Distribution bar = 14 Bars.

Cutting Length of one Footing Main Bar:

Length = {Total size – 2(Half diameter of the bar + Clear cover) + 2(Thickness of the slab –Bottom and Top clear cover – Diameter of the bar – Half diameter of the bar)}.

Length = 2 m – 2 (0.006 + 0.05) + 2 (0.250 – 0.075 – 0.05 – 0.012 – 0.006).

Length = 2.102 m.

Total length = Length of one bar x No’s of bars.

Total length = 2.102 m x 14.

Total length = 29.428 m.

Weight of the main bar:

Weight = D^2/ 162.2 x Length.

Total Weight = D^2 /162.2 x 29.428 m.

Total Weight = 26.13 kg.

**CONCLUSION:**

Footing Main Bar =12 mm @150 c/c = 14 No’s = **20.48 kg.**

Footing Distribution Bar = 12 mm @150 c/c = 14 No’s = **26.13 kg.**

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hello, guys I just want to know how to calculate the quantities from AutoCAD dwgs.I mean for both steel and concrete and also how to calculate them by using ms excel?

Hi, the whole thing is going fіne here and ofcourse every one is sharing data, that’s

truly excellent, keep up writing.

Hey why there is +2 * thickness of slab which is 0.25 meter , I think it should be just thickness of slab, it shouldn’t be multiplied by 2.

please right me if I am Wrong?

HELLO SIR,

Calculation is wrong boss

Length = {Total length – 2(Half diameter of the bar + Clear cover) + 2(Thickness of the slab –Bottom and Top clear cover – Half diameter of the bar)}.

Length = 2 m – 2 (0.006 + 0.05) + 2 (0.250 – 0.075 – 0.05 – 0.006).

Length = 1.676 m.

Length = 2 m – 2 (0.006 + 0.05) + 2 (0.250 – 0.075 – 0.05 – 0.012 – 0.006).

= 2 – 2(0.056) + 2(0.107)

= 2 – 0.112 + 0.214

= 2.102 m

Length = 2.102 m.

there’s a mistake in computing the length of rebar…if the width of the footing is 2m…how come the total length of rebar is 1.676m only?

The Formula of the length calculation is

Length = {Total length – 2(Half diameter of the bar + Clear cover) + 2(Thickness of the slab –Bottom and Top clear cover – Half diameter of the bar)}.

When we minus those things we get this calculation.