Math & Numbers
Convert days to weeks with configurable decimal precision
days-to-weeksMath & Numbers
Convert whole days to exact calendar years from a specified start year
days-to-yearsMath & Numbers
Calculate Cohen d, Hedges g, Cohen h for proportions, or correlation r effect sizes from summary statistics
effect-size-calculatorMath & Numbers
Compute the dot product, cosine similarity, and angle between two vectors
dot-product-calculatorMath & Numbers
Compute the determinant of a square matrix and explain the main calculation steps
determinant-calculatorMath & Numbers
Check whether one integer is divisible by another and show the quotient, remainder, and optional divisibility hint
divisibility-calculatorMath & Numbers
Convert decimals into simplified fractions or mixed numbers with configurable tolerance and denominator limits
decimal-to-fraction-calculatorCalculator
Calculate elevation statistics from a list of elevation points
elevation-calculatorMath & Numbers
Calculate discounted prices, savings, and final price after applying percentage or fixed amount discounts
discount-calculatorMath & Numbers
Calculate electricity costs based on power consumption and usage time
electricity-calculatorMath & Numbers
Convert between different energy units (joules, calories, kilowatt-hours, BTU, etc.)
energy-converterFinance
Check if a string is an Ethereum address. Does not validate address checksums.
eth-address-validator