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How to Calculate a Bill of Quantities

A bill of quantities (BoQ) is a crucial component for tracking a project’s progress and costs. However, preparing one can be complicated.

It requires a thorough understanding of the drawings and specifications, as well as knowing how to use a standard method for measurement. Using an accurate BoQ promotes transparency and fairness during the tendering process.


A bill of quantities is a list of materials and components that are needed to complete a construction project. It allows contractors to submit detailed quotes for each component of the work and compare prices against one another. It also makes it easier for the contractor to understand the scope of the work, reducing disputes over unclear instructions.

Preparing a bill of quantities can be a lengthy process, but it’s essential for accurate cost planning and tendering. It should be prepared using a standard methodology to reduce errors and misunderstandings. A bill of quantities must be accurate because even a minor mistake could significantly affect the overall costs of a project.

A BoQ is generally completed by a quantity surveyor, cost consultant or civil engineer who has a specific expertise in estimating material quantities. It is usually produced after the design is complete and a specification has been prepared. The quantities listed in a BoQ may be measured in terms of number, length, area, volume or weight.

When preparing a BoQ, it is important to take the time to count all of the materials that will be required. This can be done by referring to the plans and carrying out a taking off exercise. Depending on the complexity of the project, it may be necessary to divide a BoQ into different parts. This will make it easier for suppliers to price each part and may also help with the coordination of sub-contract packages.


A bill of quantities in construction breaks down the specific materials, labor, and equipment required to build a project. It is a standard document used in the tendering process and helps contractors accurately prepare their bids. BOQs are typically prepared by quantity surveyors or civil engineers who specialize in estimating materials. However, anyone can prepare a BOQ using construction estimating software. This makes the process easier and more accurate.

Contractors can use a construction estimating software to break the BOQ down by categories that reflect the work packages that will be completed by subcontractors. This allows them to calculate labor costs using local rates and prices. This will help them ensure their final cost estimates are accurate and competitive. It will also save time by reducing the number of calculations and rework that is required.

The contractor will also need to provide a cost estimate for each individual item that is included in the BOQ. This can be done by looking up the unit price for each item and multiplying it by the amount of work to be completed. The contractor will then add up all the costs to produce their total estimate for the project.

A BOQ is important because it ensures that all contractors are quoting the same scope of work. This eliminates confusion for project owners when comparing proposals from different contractors. It also allows them to easily review progress claims as the project proceeds, and anticipate cash flow needs.


Bills of quantities are used in the construction industry to provide project-specific measured quantities of items identified in drawings and specifications. They are typically prepared by a cost consultant or quantity surveyor and provide details of the materials, parts, labor and equipment required for a building. Once the BoQ is complete, suppliers tender against it, stating their price for each item. This allows the quantity surveyor to compare the prices of each supplier on a rate-for-rate basis, making it easier to assess which offer is best value for the client.

It is important to use a standard methodology when preparing a BoQ, which helps prevent misunderstandings and disputes. It is also helpful to review the BoQ with everyone involved in the estimate, including the project architect or engineer and subcontractors. This will help ensure that the BoQ reflects the final scope of work.

Once a contractor has priced out the BoQ, they can then use it to make a quote for the construction project. If the BoQ is accurate, it can help speed up the tendering process and save time. It can also be used in post-tendering activities, such as material scheduling and construction planning. In addition, the contractor can use it to calculate their rates, assisting them in managing their costs.

Subcontractor Fees

A bill of quantities is a list of materials required to complete construction works that have been outlined in tender documentation. This enables you to compare contractor quotes in thorough detail before you hire someone for the project. It also allows you to clearly define the scope of work and ensures that all suppliers quote on the same items.

Generally, a bill of quantities is prepared by a quantity surveyor in accordance with standard methods of measurement such as SMM7 or NRM. It contains a detailed description of each item of work and specifies the basic measurements used to calculate the cost of that particular type of building work.

Different parts of a project are likely to be completed by subcontractors, so the Bill of Quantities can be broken down into work sections that reflect subcontractor contracts. This makes it easier for contractors to compare the prices for each item of work, as well as for the overall cost of the project.

The Bill of Quantities also includes a schedule of rates, which is used to assess the costs of labour, plant and equipment, as well as overheads and profit. It can also be used to determine the time to complete each part of the work and to estimate the number of hours needed to complete the job. Using the schedule of rates also helps when valuing variations and preparing interim payments.