Market share
In short
Market share is the portion of total sales in a defined market that a single company holds. You calculate it by dividing your sales by the total sales of everyone in that market, then multiplying by 100.
It shows position against competitors. It does not show headroom: that is market penetration, which compares your customers with all potential buyers.
How to calculate market share
Say total annual sales in a segment are $200 million and your sales are $10 million. Your market share is 5 percent. The numbers are for illustration only.
The hard part is the denominator. Define the market clearly and use the same definition each period, or trends will mislead you.
Ways to measure it
- By revenue: Your revenue divided by total market revenue. Most common for B2B.
- By units or customers: Your customers divided by all customers in the market. Useful when prices vary widely.
- By segment: Share within one segment, which is often more actionable than a global figure.
Why GTM teams track it
Spot where you win and lose
Share by segment shows where you are strong and where rivals lead, which guides where to invest.
Set realistic targets
Growth plans are easier to defend when tied to a share goal in a defined segment.
Read the competitive trend
Rising sales with falling share means rivals are growing faster than you.
Common mistakes
- Vague market definition: Without a clear boundary the figure cannot be reproduced.
- Relying on guesses for competitor sales: Use credible sources, and say how uncertain the estimate is.
- Treating share as the goal: Buying low-fit customers to raise share can hurt retention and margin.
Market share FAQs
What is market share?
Market share is the percentage of total sales in a defined market that one company holds. It is calculated by dividing the company's sales by total market sales and is used to compare competitive position.
How do you calculate market share?
Divide your sales in the market by the total sales of all companies in that market, then multiply by 100. For example, $10 million of $200 million total sales is 5 percent. Keep the market definition consistent over time.
What is the difference between market share and market penetration?
Market share compares your sales with competitors' sales in the same market. Market penetration compares your customers with all potential customers, including those who buy from no one. Share shows rank; penetration shows remaining room to grow.
How can a company increase its market share?
Focus on segments where you fit best, win accounts from alternatives, improve retention, and expand within existing customers. Raising share only through low-fit customers can hurt churn and margins, so keep your ICP in view.
