Calculators
Convert units, calculate percentages, fractions, statistics and weighted averages, change number bases or pick random list entries with clear precision limits.
Explore tools
Unit converter
Convert length, area, mass, volume and temperature with compatible units side by side.
Percentage calculator
Find a share, calculate an amount from a percent, or measure percentage change.
Aspect ratio calculator
Reduce a width and height to a ratio, then plan a proportional pixel size.
Data size converter
Convert bit and byte amounts across decimal MB/GB and binary MiB/GiB units.
Number base converter
Convert large integers exactly between binary, octal, decimal, hexadecimal and other bases.
Random number generator
Draw integers from a chosen range, with or without repeats, and copy the result in order.
Fraction calculator
Add, subtract, multiply and divide fractions, mixed numbers and finite decimals exactly.
Statistics calculator
Calculate list mean, median, variance and standard deviation, or exact decimal statistics for a CSV column.
Weighted average
Pair values with relative or percentage weights and calculate their weighted average.
Numeric rounding and formatting
Round exact decimal input to decimal places or significant digits, or write scientific notation.
Linear interpolation
Estimate Y from two known X/Y points and a target X.
Permutations and combinations
Count ordered arrangements and unordered selections exactly from n distinct items.
Random list picker
Pick one or more names or items from a line-by-line list without reusing a selected line in the same draw.
Neutral chemical-equation balancer
Balance explicitly declared neutral formulas with exact rational arithmetic, preserving the full element matrix, nullspace basis and conservation proof without guessing nonunique solutions.
Formula composition and declared-weight mass
Count every repeated element in neutral formulas, then calculate each contribution and the total using a versioned weight table or your explicit decimal weights.
Choose the right tool
Select the operation and its assumptions before entering values. Fractions and integer operations preserve exact quantities where supported; floating-point statistics have different precision limits. Review units, weights, rounding rules and sample versus population settings.