Create secure random UUID v4 values.

Calculate voltage-divider output or solve R2 for a target voltage.

Convert liters, gallons, cups, fluid ounces, and cubic units.

Solve wavelength, frequency, or wave speed with v = fλ.

Calculate ISO week numbers and week-years.

Convert kilograms, pounds, ounces, grams, stone, and tons.

Instant word, character, line, and reading-time counts.

Solve mechanical work, force, or distance with W = Fd cos(θ).