Calculators for customer teams.
Six free tools for the numbers that matter — NPS, CSAT, churn, lifetime value, health scores and sample size. Real, deterministic math that runs entirely in your browser: nothing is uploaded, stored or sent anywhere.
NPS Calculator
Turn detractor, passive and promoter counts into your Net Promoter Score on the classic -100 to +100 scale.
CSAT Calculator
Work out your Customer Satisfaction score from positive responses and total responses in seconds.
Churn Calculator
Monthly and annualised churn rate from the customers you lost over any period — plus a 12-month projection.
CLV Calculator
Customer lifetime value from average order value, purchase frequency and lifetime, adjusted for margin.
Health Score Calculator
Weight six 0–100 signals — satisfaction, sentiment, loyalty, engagement, retention, support — into one score.
Sample Size Calculator
How many survey responses you actually need at 90%, 95% or 99% confidence and your chosen margin of error.
Calculators are snapshots. ClientTell is a live feed.
Every number above is one your product can track for you automatically — from the feedback your customers are already giving.