You may not have had ‘A’s in math. Can you still manage a project?
This is what you will find out in this article. I will give you an overview of how maths is used in project management, and then you can see for yourself if you feel good about your level of maths for becoming a project manager.
High school math is enough for 95% of project management
Yes, that’s a fact. Unless you want to manage $10M projects, your high school math skills will be sufficient. Because in most projects you’ll only need basic arithmetics — adding up and subtracting numbers, carrying out divisions and multiplications.
The main step where your numbers skills are required is for setting up a budget. Together with your team, you’ll have to make estimations for work and cost. You’ll have to break down numbers on the timeline – what amounts are incurred in each month. This is basic arithmetics. More than maths skills, the planning stage will be a test of your critical thinking abilities. ‘Do the numbers which I got from my team look plausible?’ is a question you have to ask yourself. If for example, any effort estimations are too low, that’s going to haunt you later, because you’ll have to go begging for extra budget and additional resources. But that’s not what you want, so before you submit your budget for approval, you carefully have to review the numbers and use your ‘bullshit detector.
Here are some examples of calculations you have to do as a project manager:
Adding up budget values:
To make budget planning easier, you may want to use an Excel spreadsheet as I do. I use a budget tracker which you can get as part of my Project Template Pack. You can also find my other budget tracker alternatives here.
And if you are totally new to project budgeting, I have a video course where I walk you through the entire process of planning out a project budget.
Working with percentages:
Interestingly, many people struggle with calculating percentages. But it is a very important skill that is very helpful beyond project management.
For example, you may want to calculate the tax charges on an item to be purchased. Suppose the item costs $760 and you have to pay 12% sales tax. Then the tax amount will be $760 x 0.12 = $91.2 and the total purchase value will be $760 + $91.2 = $851.2. Easy right?
But now imagine you only knew the gross price of a product and you wanted to know the net price (the cost excluding tax). Let’s say the gross price was $2470.81. What would be the net price, assuming the sales tax rate is 12%? We need to do the calculation from before backward. So in this case you would calculate: $2470.81 / 1.12 = $2206.08, which is the net price of the item.
You may wonder why I show you such calculations concerning purchases. As a project manager, you will also be making purchases of materials and services, and therefore it is helpful if you are proficient in working with percentages.
Rule of three:
Apart from basic addition and subtraction as well as percentages, a solid understanding of the ‘rule of three’ is probably very helpful. It shouldn’t be new to you.
Here’s a practical example of the ‘Rule of three’:
You are in charge of a construction project, involving the construction of a 3km road section. Your initial plan foresaw a performance of 60 m completed per day, relying on a team of 10 construction workers, which would take the project 3000 m/60 m = 50 days to complete. You are at the end of day 8, and the team has completed only 300 m. Assuming the construction work continues at the given rate, when will the project be finished? I will leave the calculation to you, but the mathematical ‘tool’ to be used here is the Rule of three.
When do you need advanced math skills?
I said earlier that for 95% of projects, basic high school maths is all you need. So what are the 5% of projects?
In general, projects that use more advanced math concepts are big investment projects (think of large construction projects) or complex manufacturing projects. Oftentimes, those projects involve more advanced algebra and the use of statistics to evaluate metrics like product quality, progress, financial performance and other relevant key figures. However, as a project manager, it is unlikely that you will do the numbercrunching yourself — that’s what your team is doing, But you definitely should understand the underlying mathematical concepts and be able to interpret and visualize the numbers.
That leads me to one key point I want to make:
It’s all about interpreting and communicating numbers
Being in charge of a project, you will be working with numbers almost every day. Most of the time, these numbers are provided to you by your team members, suppliers, customers and other stakeholders, and they will be used further down the line for decision making and other purposes. That’s when your ability to critically review numbers becomes very important, much more important than your math skills. You need to ask yourself: Are these numbers plausible? What do these numbers tell me? What are the consequences? Are you still within budget?
The other skill you need to hone is communicating numbers. As a project manager, you frequently have to give updates to the management. What does management care most about, apart from the overall project status? It’s the cost. So you need to find a way to present the cost information in a clear fashion that leaves no room for interpretation. Although I have an update template you can use, I can’t give you more detailed tips here because every project is different, and so how to best present the cost details really depends on the project.
Your math skills won’t tank your project
With solid highschool level math skills under your belt, you will easily manage the numbers of a project without looking dumb. Much more important than your math skills are critical thinking and communication skills. Also, remember that you are part of a team and that it is ok to ask for help or feedback. Numbers are a delicate thing, and that’s why you should always have a coworker doublecheck your numbers before you submit them. I always do so.
I wish you the best of luck for your future. Check out the other guides in the career section. Here is the link to my project management courses that you might want to take a look at if you want to gain realworld PM skills.
Author

Hi! I’m Adrian, founder of Tactical Project Manager and a Project Manager with over ten years of experience. Managed largescale IT implementations and business projects. I started Tactical Project Manager to offer you a straightforward and pragmatic approach to project management, enabling you to lead any project with confidence.
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