Math & Numbers
Calculate sample and population skewness to measure distribution asymmetry
skewness-calculatorMath & Numbers
Calculate sample standard deviation from sample variance using the n - 1 denominator
sample-standard-deviation-calculatorMath & Numbers
Calculate sample variance with the n - 1 denominator for estimating spread from a sample dataset
sample-variance-calculatorMath & Numbers
Calculate arithmetic, geometric, and Fibonacci sequences, including the nth term, the first terms, and the partial sum
sequence-calculatorMath & Numbers
Round numbers to integers, decimal places, tens, or hundreds using a simple rounding mode selector
rounding-calculatorMath & Numbers
Count significant figures and round numbers to a target number of significant digits
sig-fig-calculatorMath & Numbers
Calculate square roots, check whether a value is a perfect square, and verify the squared result
square-root-calculatorMath & Numbers
Add, subtract, multiply, and divide values written in scientific notation, then return standard, scientific, and engineering forms
scientific-notation-calculatorMath & Numbers
Convert numbers between standard decimal format and scientific notation, with optional engineering notation output
scientific-notation-converterMath & Numbers
Estimate required sample size for proportions or means using confidence level, margin of error, and optional finite population correction
sample-size-calculatorMath & Numbers
Run one-sample or two-sample t-tests from raw data and inspect t statistics, degrees of freedom, and p-values
t-test-calculatorFinance
Find, convert and normalize currency values within text content
text-currency-normalizer