Tools
Every tool is defined by a spec (inputs, outputs, assumptions) and ships with golden test vectors.
All tools
Average power calculator
Compute average power from energy and time (P = E / t), with unit conversion.
BMI calculator
Calculate body mass index (BMI) from weight and height, including standard BMI categories.
Board feet calculator
Compute lumber volume from thickness × width × length, and view results in board feet.
Circle area calculator
Compute the area of a circle from its radius, with unit conversion.
Circle circumference calculator
Compute the circumference of a circle (C = 2·π·r), with unit conversion.
Compound interest calculator
Compute compound interest final amount (A = P·(1 + r/n)^(n·t)).
Concrete volume calculator
Estimate concrete volume from slab length, width, and depth, with unit conversion.
Cone volume calculator
Compute the volume of a cone from radius and height (V = 1/3·πr²h), with unit conversion.
Cylinder surface area calculator
Compute total surface area of a cylinder (A = 2·π·r·(r + h)), with unit conversion.
Cylinder volume calculator
Compute the volume of a cylinder from radius and height (V = πr²h), with unit conversion.
Kinetic energy calculator
Compute kinetic energy from mass and velocity (E = 1/2·mv²), with unit conversion.
Loan payment calculator
Compute monthly payment, total payment, and total interest for a fixed-rate amortizing loan.
Percent change calculator
Compute absolute and percent change between an old value and a new value.
Pythagorean theorem calculator
Compute the hypotenuse length from two perpendicular sides using √(a² + b²).
Rectangle area calculator
Compute the area of a rectangle from length and width, with unit conversion.
Rectangle perimeter calculator
Compute the perimeter of a rectangle (P = 2·(L + W)), with unit conversion.
Simple interest calculator
Compute simple interest and final amount (A = P·(1 + r·t)).
Sphere surface area calculator
Compute the surface area of a sphere (A = 4·π·r²), with unit conversion.
Sphere volume calculator
Compute the volume of a sphere from its radius (V = 4/3·πr³), with unit conversion.
Trapezoid area calculator
Compute the area of a trapezoid from both bases and height, with unit conversion.
Triangle area calculator
Compute the area of a triangle from base and height, with unit conversion.