Fit zero-order, first-order, and second-order rate equations to concentration-time data. Get reaction order, rate constant k, half-life t½, and R² goodness-of-fit.

Finance

Pay Raise & Real Purchasing Power Calculator

Compare a raise or job offer after inflation, convert salary periods, and check whether longer hours erase your hourly gain.

Calculator

Overtime & Hourly Wage Bi-directional Converter

Converts pay bi-directionally (hourly ↔ monthly ↔ annual) under four overtime regimes — US FLSA 1.5x over 40h/week with bonus-blended regular rate, China’s 150/200/300% tiers off the 21.75-day month, and contractual-multiplier EU/UK with 48h-average checks — pricing weekday, weekend and holiday overtime, night-shift premium and annual bonus, with itemized subtotals, effective hourly rate and compliance warnings.

Math & Numbers

Multiplicative Order Calculator mod n (ordₙ(a))

Smallest k with a^k ≡ 1 (mod n) via φ(n) reduction: power table, minimality proof, cyclic subgroup <a>, primitive-root and maximal-order flags.

Math & Numbers

Partial Fraction Decomposer (Rational Functions)

Decompose N(x)/D(x) into A/(x−r)^j + (Bx + C)/((x−α)² + β²) with long division for improper fractions and numeric residual verification.

Math & Numbers

Inverse Laplace Transform Calculator (Partial Fractions)

Partial-fraction inverse Laplace transform for proper rational functions: root factorization (real + conjugate pairs), exact coefficient system, term-by-term inversion.