Sales & marketing · Calculator companion · By K Imports
Net Promoter Score: practical guide
This guide explains how to use the Count.ie net promoter score. Calculate NPS from promoter, passive and detractor response counts. Follow the inputs, method and worked example below, then compare your own scenario.
Guide written .
Open the Net Promoter Score calculatorWhat to prepare
- Define the event, conversion, customer and attribution period before collecting data.
- Use spend and outcomes from the same reporting window.
- Distinguish revenue, contribution profit, recurring revenue and customer lifetime assumptions.
Understand the inputs
The calculation method
NPS = 100 × (promoters − detractors) ÷ all responses.
Worked example
Illustrative inputs and their result.
Example inputs
- Promoters: scores 9–10
- 120
- Passives: scores 7–8
- 50
- Detractors: scores 0–6
- 30
Calculated example result
- Net Promoter Score
- 45
- Responses
- 200
How to interpret the result
A marketing metric depends on its attribution and cost definitions. A favourable ratio is not proof that advertising caused every sale or that future customers will behave the same way.
Compare campaigns with the same attribution window and outcome definition. Test a lower conversion rate or shorter retention period before extrapolating a promising result.
Common mistakes to avoid
- Do not double-count a customer or conversion reported by multiple channels.
- Revenue is not the same as profit available to fund acquisition.
- Small samples and changing cohorts can produce unstable comparisons.
Assumptions and sources
NPS is a score from −100 to 100, not a percentage. Survey sampling and non-response affect how representative it is.
If your case falls outside this scope, use a more suitable calculator or contact us about an unclear method.