@wzo/calc

@wzo/calc is a precision math + number formatting library with expression evaluation support and zero runtime dependencies.

Why this library

JavaScript's native floating-point arithmetic has precision issues:

0.1 + 0.2 // 0.30000000000000004
0.3 - 0.1 // 0.19999999999999998
0.1 * 0.2 // 0.020000000000000004
Number(1.005).toFixed(2) // "1.00"  (should be "1.01")

@wzo/calc produces exact decimal results:

calc
('0.1 + 0.2') // "0.3"
calc
('0.3 - 0.1') // "0.2"
calc
('0.1 * 0.2') // "0.02"
calc
('1.005', { 
_fmt
: { 
decimals
: 2, 
rounding
: 'round' } }) // "1.01"

Core features

• Precision arithmetic — internally represents numbers as "digits × 10^(-exp)" using BigInt; all rational operations are strictly correct
• Rich formatting — thousands separators, percent, compact notation, fractions, scientific notation, European / Indian styles, 6 rounding strategies, type-friendly object-based configuration
• Chaining API — chainAdd(10).sub(3).mul(2)()
• Aggregation — calcSum / calcAvg / calcMedian / calcMax / calcMin
• Zero runtime dependencies — ~12KB gzip, works in browser and Node
• Full TypeScript — type inference included