Instant answers with real-time (AJAX) updates
Most popular calculators
t-statistic Calculator
Calculate the t-statistic (t value) from sample data. Get t score, degrees of freedom (df), and p-value for common t-test setups.
t-test Calculator
Run a t-test online: one-sample, two-sample (independent), or paired. Get t statistic, degrees of freedom, p-value, and decision instantly.
Outlier Calculator (Tukey Fences)
Find outliers using Tukey’s fences (IQR method). Calculate Q1, Q3, IQR, lower/upper fences, and list mild or extreme outliers fast.
VO₂ Max Calculator
Estimate VO2 max from common inputs like pace, time, or test results. Get an easy cardio fitness score and interpretation.
Running Split Calculator
Marathon Pace Calculator
Convert marathon finish time to pace per mile or km instantly. Includes split guidance for steady pacing and race planning.
Power Analysis Calculator
Calculate statistical power or required sample size using effect size, alpha, and test type. Ideal for t-tests and z-tests. Fast & free.
Bench Press 1RM Calculator
Estimate your bench press one-rep max from weight and reps. Includes common formulas and training max percentages.
Sample Size Calculator
Calculate sample size using confidence level, margin of error, population size, and expected proportion. Perfect for surveys, polls, and research.
Margin of Error Calculator
Calculate margin of error using sample size, confidence level, and proportion (p). Ideal for surveys, polls, and confidence intervals.
Percentile Calculator
Calculate percentiles from any dataset. Find the percentile value (e.g., 90th) or percentile rank of a score. Fast, free, and accurate.
Variance Calculator
Calculate sample or population variance from any dataset. Get instant results with clear step-by-step output.