Calculators

Research calculators

Free online calculators: NPS, CSAT, sample size, margin of error, response rate, statistical significance. Calculate metrics in seconds.

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Loyalty and satisfaction metrics

Calculators for NPS, CSAT, CES and other feedback metrics

NPS calculator

Calculate Net Promoter Score from 0–10 ratings. Formula: % promoters − % detractors

CSAT calculator

Customer Satisfaction Score — share of top-2 box on a 1–5 scale

CES calculator

Customer Effort Score — average ease rating on 1–5 or 1–7 scale

eNPS calculator

Employee NPS — employee loyalty. Same as NPS for HR surveys

SUS calculator

System Usability Scale — usability score from 10 items (0–100)

Top-2 / Top-3 box

Share of responses in top N scale points. For CSAT and similar metrics

Statistics and sampling

Sample size, margin of error, confidence intervals

Sample size calculator

How many respondents? Cochran formula with FPC correction

Margin of error calculator

How much sample results may differ from the true value

Confidence interval

Interval that contains the true value with a given probability

Quota planner

Split sample by segments (gender, age, region) with target shares

Median and percentiles

Enter numbers — get median, quartiles Q1/Q3 and percentiles

Minimum sample for group comparison

Sample size per group to compare two proportions or means (power, MDE)

Cronbach's alpha

Scale reliability: internal consistency. Enter item scores — get α

Chi-square

Test association of two categorical variables. 2×2 or up to 5×5 — χ² and p-value

Pearson correlation

Linear relationship of two variables. Enter X and Y — get r, r², p-value

Coefficient of variation

CV = (SD / mean) × 100%. Compare spread across different scales

Research planning

Response rate, A/B tests, ROI

Response rate calculator

Calculate response rate or plan how many invites to send

Completion rate calculator

Share of respondents who finished the survey (completed / started × 100%)

Invites needed

How many people to invite to get the desired number of responses

A/B sample splitter

Split sample between A/B/C test variants evenly or by weights

Survey ROI

Estimate return from feedback programs: churn reduction, conversion lift

Statistical significance

Hypothesis testing, p-value, A/B significance

A/B test significance

Is the conversion difference significant? Z-test for two proportions

P-value calculator

Get p-value from z for one-tailed or two-tailed test

Frequently asked questions

Are the calculators free?

Yes. All calculators on this page are free. Data is not stored — calculations run in your browser.

How do calculators differ from surveys in SurveyNinja?

Calculators are tools for quick math on data you already have. In SurveyNinja you create surveys, collect responses, and metrics (NPS, CSAT) are calculated automatically in real time.

Can I automate metric calculation?

Yes. Create an NPS or CSAT survey in SurveyNinja — the platform calculates metrics and shows trends. Export via API or webhooks.

What formulas do the calculators use?

Each calculator page describes the formula. We use standard methods: NPS (Bain), Cochran for sample size, z-test for significance.

Which calculator should I use?

Loyalty — NPS or eNPS (employees). Satisfaction — CSAT. Ease — CES. Planning sample — sample size calculator. A/B results — significance calculator.

Can I order a full research project?

SurveyNinja offers survey creation and collection. For full-service research, see our pricing and contact options.

Is there a limit on calculations?

No. Calculators run in the browser without registration. Use them as much as you need; data is not sent anywhere.

Can I embed a calculator on my site?

You can link to calculator pages or open them in an iframe. Use the direct URL (e.g. /tools/nps-calculator).

How are metrics calculated in SurveyNinja?

In SurveyNinja, NPS, CSAT and other metrics are calculated automatically from responses; reports and charts update in real time.

What's the difference between NPS and CSAT?

NPS measures loyalty and willingness to recommend (one question 0–10). CSAT measures satisfaction with a contact or product (usually 1–5). Use NPS for overall loyalty, CSAT after support or purchase.

Automate your metrics

In SurveyNinja, NPS, CSAT and more are calculated automatically. Create a survey in 5 minutes and get real-time analytics.