How To Calculate Window Grill Quantity

In this post, you’re going to learn how to calculate window grill quantity for a building.

In fact, this approach always helps me to quickly get the required quantity of MS grills for any apartment of my project.

So if you’re working on a high-rise building project, this post will help you be organized and order the required grills whenever you need them.

Not only that, but you’ll also learn how to calculate the required materials for the window grill.

So, let’s first learn…

How To Calculate Window Grill Quantity?

Nowadays, a grill is an essential part of a window.

Most of the time, It’s made with Mild Steel bars. That’s why it’s also called MS grill.

It’s mainly used for safety purposes.

Before starting plasterwork, you need to fix grills into window openings.

For that, you have to calculate the required grill quantity first.

And, here is the step-by-step process of calculating the window grill quantity.

Step-1: Calculate The Number Of Windows

For that, get the floor plan from the architectural drawing book.

Let’s say, we have the following plan:

Floor Plan

This is an example of an apartment on a floor plan.

Like this, a building must have several floors.

And, on each floor, you’ll find several apartments. Each apartment will have a different name like this:

Name of apartments on a floor

Let’s say, the name of our example apartment is 2A.

It means the apartment is “A” type and it’s located on the second floor.

As you’ll have many apartments on a building, ordering window grills and remembering them will be difficult at the end.

Because you’ll forget which apartment you ordered MS grills for and which not.

To solve this problem I use a format in my project to count and keep records of them.

Here is that format:

Windows grill calculation format

You’ll learn using this format as you’ll learn to calculate the window grill quantity below.

For that:

First, Get The Window Schedule

You’ll get that in the architectural drawing book.

It looks like this:

An example of window schedule on a building

As you can see in the above image, there are four different types of windows. And they are named as w1, w2, w3…etc.

Now, Count The Window

For that, get the architectural plan:

Floor Plan

From the drawing:

  • w1 = 3 nos
  • W2 = 1 nos
  • W2a = 1 nos
  • W3 = 1 nos.

Step-2: Calculate The Grill Size

There is a difference between window size and window grill size.

For example, the size of our w1 window is 5′-0″×4′-6″.

But the grill size should be 5′-0″×4′-4½″.


Because we make a rainwater barrier below the grill:

Calculating the height of window grill

The rainwater barrier is made with cement concrete. And the height of this is 1½″.

So, when calculating the grill height you just need to deduct this height from the window height.

The width will be the same as the window width.

With this, the grill size of our example apartment will be:

Calculating window grill size

Now, you can easily…

Step-3: Calculate The Area Of Grills

The formula is,

= Number of windows × Width × Height

So, for our example apartment,

  • W1 = 3 × 5′-0″ x 4′-4½” = 65.62 sq.ft.
  • W2 = 1 × 3′-6″ x 3′-4½” = 11.81 sq.ft.
  • W2a = 1 × 3′-6″ x 4′-4½” = 15.31 sq.ft.
  • W3 = 1 × 2′-0″ x 1′-10½” = 3.71 sq.ft.

Put these values into the format like this:

Calculating window grill area

With this, the format is completed for our example apartment (2A).

Similarly, calculate window grills for the rest of the apartments of your building project.

Once you have this format completed, you can order MS grills for any apartment whenever you want.

Let’s see…

How To Order The Required Quantity Of Window Grills

We normally hire a grill workshop to make MS grills.

And, give them a list of grills with size and quantity.

For example, if you want to order grills for our example apartment you just need to make a list like this:

Ordering window grills

As you can see, you don’t need to calculate the area of grills while ordering.

Then why do we calculate the area?

Because we need them for paying to the grill workshop.

Grills are normally paid as square feet.

In some construction companies, they have a team to make window grills.

In that case, you may need to buy materials for making grills.

For that, you have to…

Calculate Materials For Making MS Grill

To calculate materials…

First, Get The Grill Design

You may find the design of window grills in your architectural drawing book.

If you don’t, consult with the architect and get the design.

Let’s say, we got the following design for our apartment:

Grill design example

With that:

Next, Study The Grill Design

As you can see in the above image, we have one-inch solid bars all around the grill.

And, the size of the inside bars is ½″ × ½″ solid bars.

Now, Calculate The 1” Thick Bar

The Length of the one-inch thick bar is,

= (2 × 5′) + (2 × 4′-4½″)

Calculating materials for MS grill

= 18′-9″ or 18.75′

Say, 19 feet.

So, the volume is,

= Length × Area

= 19′ × 1″ × 1″

= 0.12 cubic feet [1″=0.08 feet.]

And, the weight is,

= Volume × Density

= 0.12 × 222 [Density of mild steel = 222 kg/ft3]

= 26.64 kg

Say, 27 kg.

After That, Calculate The ½” Thick Bar

Length of ½ bar is,

= (9 nos × 4′-4½″) + (4 nos × 5′)

MS bar calculation for grills

= 39.33′ + 20′

= 59.33 feet.

Say, 60 feet.

So, the volume is,

= Length × Area

= 60′ × ½″ × ½″

= 0.096 cubic feet. [½ = 0.04 feet]

And the weight is,

= Volume × Density

= 0.096 × 222 [Density of mild steel = 222 kg/ft3]

= 21.32 kg

Say, 22 kg.

Now, Calculate The Hole Fast

Hole fast normally made with MS angle.

We have 4 numbers of hole-fasts in our grill design.

Hole fast calculation for MS grill

The length of these angles is,

= 4 × 6″

= 2 feet. [6″ = ½ foot.]

So, the volume is,

= 2′ × (1″ + 1″) × 3mm

= 2′ × 2″ × 0.01′ [3mm = 0.01 feet.]

= 0.0034 feet. [2″ = 0.17 feet]

And, the weight is,

= Volume × Density

= 0.0034 × 222 [ Density of mild steel is 222 kg/ft3.]

= 0.75 kg.

[NOTE: Sometimes, MS hollow bar is used instead of solid bars. In that case, you somehow need to get the unit weight of the hollow bar.]

Finally, Summarize Grill Materials

  • 1″ × 1″ MS solid bar = 27 kg
  • ½″ × ½″ MS solid bar = 22 kg
  • 1″ × 1″ MS Angle = 0.75 kg

This is the weight of materials for one grill only. And, the grill is named w1 in our example.

And, we have three numbers of that.

So the materials for all the w1 window grills:

  • 1″ × 1″ MS solid bar = 27 × 3 = 81 kg
  • ½″ × ½″ MS solid bar = 22 × 3 = 66 kg
  • 1″ × 1″ MS Angle = 0.75 × 3 = 2.25 kg

Follow this procedure to calculate materials for the rest of the grills.

And, write into the format like this:

Required materials for making window grill


Calculating the window grill quantity is easy.

You just need to accumulate similar size windows together.

After that, deduct 1½″ from the height of the window to get the grill height.

That’s it!

And, while calculating the MS grill materials, first study the grill design and calculate the weight.

Your Turn:

Now I’d like to hear from you:

Do you need to calculate grill materials?


You just calculate window grill quantity?

Either way, let me know by leaving a comment below right now.

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