One of the most important steps when planning a construction or renovation is to determine how much material you will need. For many projects, this means calculating linear meters, as many of the common building materials, such as wood and steel, for example, are sold and measured by the meter. Furthermore, with the correct measurements, linear meter values can be easily extrapolated to square and cubic meters. Therefore, figuring out how to find the linear meters of material needed for a project is an essential skill for any renovation specialist.
Method 1 of 2: Finding the Linear Meters of a Material in a Design
Step 1. Divide your design into different material categories
All construction projects and the vast majority of renovations involve assembling separate raw materials to form a whole. In order to be able to determine how many linear meters of each type of material your project will need, you will first need to divide everything into categories, grouping the identical materials together.
- As an example, let's pretend we're planning a relatively simple project: building a bookcase. Let's say the sides are made of 5 x 10 wooden planks and the top, base and the three middle shelves are 2.5 x 30 planks. In this case, we would divide our building materials into two categories: 5 x 10 boards and 2.5 x 30 boards.
Step 2. Use a measuring tape or ruler to measure each piece
Once you know what materials you will use in your project, measure the length of each individual part. Since we are dealing with linear meters, and not squares, for example, we don't need to worry about the thickness or width of the materials. Be careful not to measure the same pieces multiple times; making an outline of the project and labeling each piece with its length can help.
- In our example, let's say the 5 x 10 boards we're using for the sides of the shelf measure 2, 4 meters and that the 2, 5 x 12 plates measure 1.8 meter.
Step 3. Add up the lengths of the different materials
The next step is to add up the lengths of individual parts made of the same element to find a total length value for each material. This value represents the length of material you need to purchase in one piece for your project and cut into smaller pieces as needed. If your project contains several pieces of the same material with equal lengths, save time by multiplying the length of one of these pieces by the number of them.
- In our example, since we have two 2.4 m side pieces made from 5 x 10 boards and five pieces made from 2.5 x 30 boards (the three shelves, plus the top and bottom), we can figure out the totals. multiplying like this:
- 5 x 10 boards: 2, 4 x 2 = 4, 8 meters
- 2.5 x 30 boards: 1, 8 x 5 = 9 meters
Step 4. Use your totals to determine the cost of your materials
Once you know how much of each material you'll need for your project, you'll know how much you'll need to buy. Find the price per meter of each type of material and multiply by the total linear meters obtained to find the approximate cost.
- In our example, we need 4.8 m of 5 x 10 boards and 9 m of 2.5 x 30 boards. Let's say that the first one costs R$1.50 per meter and the second R$2.25 per meter. In this case, we would determine the costs of these materials by multiplying as follows:
- 5 x 10 boards: 1, 5 x 4, 8 = BRL 7, 20
- Tables of 2.5 x 30: 2, 25 x 9 = BRL 20, 25
Step 5. Convert your meter measurement to other units if necessary
Not all building materials are sold in linear meters; some use different units of measure, while others are sold in units that are not of length (such as units of area, volume, etc). If your materials are sold in another unit of length, convert the linear meters to that new unit before calculating prices. Usually, it's just multiplying or dividing by a constant. Below are instructions on how to convert meters to several other common length units:
- Meters to centimeters: multiply by 100
- Meters for feet: multiply by 3, 2
- Meters to Inches: Multiply by 40
- Feet to Yards: As 1 yard = 1.09 meters, the measurement is practically the same
Step 6. Be conservative when making your purchase
When it comes to projects, one of the most common tips is to always buy a little more material than you think you'll need. That way, you'll have "room to maneuver" in case you make mistakes in the calculations or during the project. Although the price of your materials does go up a bit this way, it's generally a smart idea as it eliminates the hassle of running back to the store if you run out of materials in the middle of the project. Also, extra materials can be saved for future projects.
- In our example, we calculate that we will need about 4.8m of 5x10 boards and 9m of 2.5x30 boards. For safety it might be better to buy 6 m and 10, 5 m, respectively. If we have leftovers, we can use them to place vertical dividers on some shelves.
Method 2 of 2: Using Linear Meters to Find Other Values
Step 1. Find the square meters using the width and length
Once you know the length of all the materials you need for your project, you can use that information to make other related calculations. For example, since the two-dimensional area of a rectangular space is length times width, you can use the length measurements of materials that form rectangles to find the area of the object formed by them. In that case, you just need to multiply the lengths. Note that to get the values to calculate the area correctly, some extra measurements may be needed.
- Let's go back to the example above. Let's say we want to cover the entire back of our bookcase with particleboard, which, for our purposes, is measured per square meter rather than linear. In this case, since the sides of the bookcase are 2.4 m high and the top and bottom parts are 1.8 m long, it might look like we need to multiply 2.4 by 1.8 to get the answer. Nonetheless, this result does not take into account the thickness of the 5 x 10 boards used as sides of the shelf and that make the piece of furniture a little more than 1.8 m wide.
- Let's say, after measuring, we find that the 5 x 10 boards are 5 cm thick. Since the bookcase has two side plates, this measurement is about 10 cm, or a tenth of a meter wider than 1.8 m. So, to find the area of the plate we need, we'll multiply it as follows:
- 2,4 x 1,9 = 4, 56 square meters
Step 2. Know the area equations for non-rectangular shapes
Not all projects will only deal with rectangles: many other shapes are possible. If you find a simple shape like, for example, a circle or a triangle, you can just put an easy-to-get value into a specific equation to get values for the shape's area. As long as your measurements are all in meters, your answer will be in square meters. Below are some area equations for certain common shapes:
- Circle: π(r)2 - r is the distance from the center of the circle to its edge (the radius).
- Triangle: (hb)/2 - b ("base") is the length of one side and h ("height") is the length of the line from the opposite point that meets the base at a right angle.
- Square: l2 - l is the length of one side.
- Trapeze: (1/2)(a + b)(h) - a and b are the lengths of two parallel sides, and h is the distance between them.
Step 3. When possible, divide irregular shapes into regular smaller shapes
Some projects will use two-dimensional shapes for which a simple area equation is not available. In these cases, try breaking the irregular shapes into several smaller regular shapes with areas that can be calculated by simple equations. In some cases, it may be necessary to split the results of an equation to accommodate the fact that only a certain part is being used.
- Going back to our example, let's say that, in addition to adding the cluster to the back of the shelf, we want to place a 0.9 m semicircle of the same material on top of the piece of furniture to put a clock on top of it. There is no simple equation for finding the area of a rectangle with a semicircle coming out of the top, but in this case we can use the value we already have for the rectangular back and add up half the area of a 0.9 m circle. radius to determine our total, as below:
- 4, 56 + (1/2)(π(0, 45)2) = 4, 56 + (1/2)(1, 41) = 5, 26 square meters
Step 4. Find cubic meters using length, width and height
Some projects will ask you for the volume of a three-dimensional space. Since volume is length times width times depth, the volume of a box-shaped object or space can be found by using the lengths of its materials to determine these dimensions and multiply. As stated above, some extra measures may be needed.
- Let's say that, in our example, we need to determine the approximate three-dimensional volume of our bookcase. We already know its height and width, so we will measure how deep the shelves are and get a measurement of 0.9 m. With these three measurements, we can find the volume just by multiplying the dimensions as follows:
- 2, 4 × 1, 9 × 0, 9 = 4, 1 cubic meters
Common formulas for determining area
- Rectangular or square shapes: length x width
- Non-equilateral triangles: (length x width)/2
- Equilateral triangles: square root of 3 divided by 4 and multiplied by the length of one side squared
- Ellipse (circular shape): length radius x width radius x pi
- Sellers will have already determined the length, width and measurement in meters of your material. Pay attention to the labels.
- Keep in mind that construction lumber is denoted in approximate measurements which may vary depending on the place of purchase.