What Total Addressable Market (TAM) Is & How to Calculate It

What Is Total Addressable Market?

Total addressable market (TAM) is the annual revenue your business would earn if you captured 100% of your market. TAM represents all possible revenue if every potential customer buys your product or service.

You can calculate your TAM with this formula:

TAM = number of potential customers in your market x average revenue per customer 

Later in this article, you will find different ways to estimate each component.

The Difference Between TAM, SAM, and SOM

• TAM: The total market demand if you achieve 100% market share
• Service Available Market (SAM): The demand for your product within the market you can serve based on constraints like geography, product limits, and regulations
• Service Obtainable Market (SOM): The portion of the SAM you can realistically capture, factoring in competition, marketing reach, and budget

Example: A project management software company focuses on small and medium-sized businesses (SMBs).

• TAM includes all SMBs worldwide.
• SAM includes SMBs the company can serve (e.g., U.S.-based).
• SOM includes the fraction the company can realistically acquire (e.g., 15% of U.S.-based SMBs).

Why Is It Important to Understand TAM?

Total addressable market is an important measure to understand because:

1. TAM validates your idea. If you are launching a new business, TAM indicates whether the market is large enough to support your venture. A large TAM implies real demand.
2. TAM conveys market potential. Investors and stakeholders want to see possible growth. Understanding TAM helps you demonstrate potential returns and secure funding or buy-in.
3. TAM informs resource needs. Knowing the market size and revenue potential guides decisions on product development, marketing budgets, and sales strategies.

How to Calculate Total Addressable Market: 3 Methods

Here are the three main approaches to calculating total addressable market:

1. Top-Down Approach

The top-down approach starts with a broad market size (from industry reports or other data). You then narrow it down to your actual market, multiply your actual market by your average revenue per customer, and get TAM.

Here’s how to calculate TAM using the top-down approach:

1. Find the total number of potential customers.
2. Use external sources to narrow that number to your specific market.
3. Calculate your average revenue per customer (or estimate it).
4. Multiply the narrowed customer count by your average revenue per customer.

Example:

• Total businesses worldwide: 400 million
• Narrow to small- and medium-sized businesses: 350 million
• Average annual spending per customer: $1,000
• TAM: 350 million × $1,000 = $350 billion

Advantages:

• Quick to calculate
• Helpful for early-stage startups that lack internal data

Disadvantages:

• Relies on external data, which may be outdated or incomplete
• Can inflate TAM if you don’t refine your target market enough

Use Semrush’s Market Explorer tool to research market size and get population estimates that help you calculate TAM.

2. Bottom-Up Approach

The bottom-up approach uses internal data (e.g., current revenue and customers). It then scales the internal data to estimate the total market value.

Here’s how to calculate TAM using the bottom-up approach:

1. Count your current customers and total annual revenue.
2. Find your average revenue per customer (annual revenue ÷ number of customers).
3. Estimate how many potential customers exist in your market.
4. Multiply the number of potential customers by your average revenue per customer.

Example:

• Current number of law firm customers: 50
• Annual revenue from these 50 firms: $125,000
• Average revenue per customer: $2,500 ($125,000 ÷ 50)
• Estimated total law firms in your market: 100,000
• TAM: 100,000 × $2,500 = $250 million

Advantages:

• Uses real sales data, making estimates more accurate
• Often more convincing for investors

Disadvantages:

• Requires existing data, which startups may lack
• May overlook expansions or changes in your business model

3. Value-Theory Approach

The value-theory method estimates TAM by determining the value you provide and the amount customers will pay for that value. You then multiply what customers will pay by the number of potential customers.

Here’s how to calculate TAM using the value-theory approach:

1. Identify the problem your product or service solves.
2. Quantify the value of solving that problem for one customer.
3. Estimate how much customers will pay for your solution.
4. Find the total number of potential customers with this problem.
5. Multiply your proposed price by the total number of potential customers.

Example:

• An AI-driven inventory management system saves an average retail store $50,000 annually.
• Retailers are willing to pay $4,800 per year for that solution.
• You estimate 100,000 stores have this problem.
• TAM = 100,000 × $4,800 = $480 million

Advantages:

• Good for innovative products without historical data
• Highlights how pricing aligns with delivered value
• Helps shape a pricing strategy

Disadvantages:

• Requires assumptions about value and willingness to pay
• May not factor in competition, adoption rates, or price sensitivity

Get the Insights You Need to Succeed in Your Market

TAM is an important metric for evaluating market potential. You can calculate TAM easily with Semrush’s Market Explorer tool:

1. Open the tool, choose “Analyze Category,” and select your target industry or niche.
2. Click “Research a market,” or select “Create List” and enter competitor domains.

3. The tool estimates your market size. Multiply the market size by your average revenue per customer to find your TAM.
4. Gain further insights, such as key market players and audience data.

Try the Market Explorer tool today to understand your market and position your business for success.