To measure customer satisfaction, you could ask shoppers to answer lengthy surveys covering everything from product quality to customer service. Or, you could ask one question—How likely are you to recommend us?—and turn the answers into a single number. This is your Net Promoter Score (NPS).
Because it reflects customer loyalty, NPS is also correlated with revenue growth. On average, an industry’s NPS leader grows more than twice as fast as its competitors, according to Bain & Company research.
Here’s how you can calculate NPS scores, along with actionable insights on how to improve your business’s score.
What is a Net Promoter Score?
Net Promoter Score was introduced by Bain & Company consultant Fred Reichheld, who set out to discover which customer survey question best predicted business growth and word-of-mouth recommendations. In 2003, following years of research, Reichheld introduced NPS in Harvard Business Review, synthesizing lengthy customer surveys into one question: “On a scale of 0 to 10, how likely are you to recommend us to a friend or colleague?”
This is the standardized NPS question that, over the decades, has become the gold standard for business leaders measuring brand loyalty. “It’s the ultimate report card from our customers,” Tom Hassell, president of the clothing brand Life is Good, says on an episode of the Shopify Masters podcast. Life is Good earned an NPS of 91, Tom says, whereas the apparel industry’s average NPS is 39. “There is no greater predictor of a company’s future success or failure than their NPS score,” he says.
There are different types of NPS:
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Relational NPS. This measures overall customer loyalty and brand perception. It follows the core NPS question and tracks how sentiment changes over time.
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Transactional NPS. This metric focuses on customer satisfaction following key moments such as purchases, deliveries, and customer support interactions.
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Employee NPS. This measures what your employees think of your business by asking staffers how likely they are to recommend working at your company to a friend or colleague, on a scale of 0 to 10.
How to calculate NPS
To measure NPS, first run surveys with the NPS question. Text (SMS) and email are two common survey methods. Aim to collect as many responses as possible; the wider the sample, the more reliable your score will be at reflecting overall customer sentiment.
Once you’ve gathered responses, group your customers into these three categories:
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Promoters. These customers answer 9 or 10 and are brand ambassadors—your most enthusiastic advocates. Bain finds they account for more than 80% of referrals in most businesses.
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Passives. Respondents who answer 7 or 8 are generally satisfied but unenthusiastic; according to Bain, their repurchase and referral rates run as much as 50% lower than promoters’.
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Detractors. Unhappy customers answer 0 through 6 and are the group most likely to leave bad reviews and spread negative word of mouth about your business.
Tally your promoters, passives, and detractors, then plug them into the NPS formula:
Net Promoter Score = [(Number of promoters - Number of detractors) / Total number of respondents] x 100
Say that out of 200 survey responses, your ecommerce business has 80 promoters, 100 passives, and 20 detractors. Subtract the 20 detractors from the 80 promoters to get 60, then divide that by 200 to get 0.3. Multiply 0.3 by 100 to get an NPS of 30.
Net Promoter Score ranges between -100 and 100 (“net” refers to the balance of customers who’d recommend your brand). A positive NPS means more of your customers would recommend your business than criticize it.
Ways to improve NPS
- Include one open-ended prompt
- Ask follow-up questions
- Look at NPS scores alongside operational data
- Track NPS alongside your referral rate
Some companies publish their NPS scores, so you could look for companies in your industry with high scores and try to learn from what they’re doing. Still, your customers are the best starting point. They gave you your NPS score, so learning more about them is the most direct way to raise it. Here’s how:
Include one open-ended prompt
Though NPS centers on Reichheld’s standardized question, once customers have answered, you can follow up with one or two open-ended questions such as, “What is the main reason for your score?” and “What could we do to improve your experience?” Digging into the “why” behind customers’ scores can reveal ways to improve your NPS.
For example, Life is Good found that its charitable work—specifically its “10% for the kids” model— came up repeatedly as a reason customers were excited to tell their friends about the brand, and as a factor driving their NPS of 91. On Shopify Masters, Tom says customers who dig deeper into a business’s charitable projects tend to become lifelong customers.
Ask follow-up questions
After you’ve conducted your NPS survey, continue the customer feedback loop. Asking passives or detractors why they’re hesitant to recommend your brand can surface customer experience issues that are dragging down your NPS score—like a strict returns policy or problems with your checkout page.
Promoters are worth engaging, too. Ask them why they rated you highly to gain insight into your company’s strengths. Thank them for their feedback and make it easy for them to share their enthusiasm on public review sites.
Look at NPS scores alongside operational data
Operational data can supplement feedback from your customers to give you a fuller picture of what’s happening with your business. A change in your NPS score tells you something has changed; the operational data gives you a clearer picture of what that is. A dip in scores that lines up with slower delivery times, for instance, points you to the issue.
This is true of both positive and negative changes. Using transactional data, the wallet and accessories brand Ridge found that their customers prefer automated customer service for its speed and accuracy. Ridge raised their NPS by handling roughly 60% of their customer service tickets using AI. After switching to automated service, NPS scores rose from about 90 to 95 to 97, says CEO Sean Frank on the Shopify Masters podcast.
Track NPS alongside your referral rate
Divy Ojha, founder of the produce-delivery subscription Odd Bunch, tracks customer health metrics using quarterly and annual cohorts. When it comes to customer loyalty, “NPS is a big one for us,” Divy says on Shopify Masters. Odd Bunch, which has surpassed 100,000 customers, pairs NPS with a second customer satisfaction metric: referral rate.
Through cohort testing, Odd Bunch found their four-week referral rate to be an even stronger predictor of long-term retention than NPS. Customers who refer at least one friend in their first four weeks are far more likely to remain subscribers after six months than those who don’t.
You can measure your business’s referral rate by surveying customers via text or email. The window you choose will depend on what you sell and the model you use. Odd Bunch’s four-week referral window is long enough for someone to have received their first delivery and used what they bought, but recent enough that they remember the experience.
NPS calculation FAQ
How is NPS calculated?
The Net Promoter Score (NPS) survey asks customers, “On a scale of 0 to 10, how likely are you to recommend us to a friend or colleague?” and groups respondents into three categories: promoters (9–10), passives (7–8), and detractors (0–6). NPS is calculated by subtracting the percentage of detractors from the percentage of promoters. Net Promoter Score ranges between -100 and 100, so any score over 0 means customers are more likely to recommend your store than criticize it.
What is the formula to calculate NPS?
The formula to calculate NPS is: Net Promoter Score = [(Number of promoters - Number of detractors) / Total number of respondents] x 100. For example, if out of 100 total respondents, 40 are promoters and 15 are detractors, you would subtract 15 from 40 to get 25, divide by 100 to get 0.25, then multiply by 100 to get an NPS of 25.
How often should you measure NPS?
When it comes to relational NPS, your survey frequency should track with how often customers buy from your business: a subscription brand might send surveys quarterly, while a furniture brand might survey customers annually. Transactional NPS surveys aren’t scheduled, but follow a specific interaction such as a delivery or a support call.
