Trade Calculator vs Constructive Calculator

Trade Calculator is the essential tool for construction professionals, sheet metal workers, HVAC technicians, and anyone who works with feet, inches, and fractions every day. Built by tradespeople, for tradespeople — this app replaces the need to carry a separate construction calculator in the field. THREE POWERFUL SCREENS: SCREEN 1 — SCIENTIFIC CALCULATOR Full arithmetic with native feet-inches-fractions support. Enter dimensions in feet and inches, choose your fraction precision (1/16, 1/32, 1/64), and get accurate results without manual conversions. Includes trigonometric functions, memory registers, and a triangle solver for angles and sides. SCREEN 2 — TRADE FUNCTIONS Purpose-built construction math at your fingertips: hip and valley rafters, jack rafters, pipe and duct offsets, column and cone layouts, and pitch calculations — all with the same fraction-friendly number pad. SCREEN 3 — DUCT CALCULATOR HVAC duct sizing based on the ASHRAE equal friction method. Enter any two of air flow, friction loss, velocity, or duct diameter to instantly solve for the remaining values. Toggle between Imperial (CFM, FPM, in.wg) and SI (L/s, m/s, Pa/m) units. Equivalent rectangular duct sizes are calculated automatically. KEY FEATURES: • Native feet-inches-fractions arithmetic (no decimal conversions needed) • Adjustable fraction precision: 1/2 through 1/64 • Scientific functions: trig, arc trig, squares, square roots • Construction trade functions: hip/valley, jack rafters, offsets, columns • HVAC duct sizing with Imperial and SI support • Equivalent rectangular duct size table • Multiple memory registers • Triangle solver (side/angle calculations) • Clean, intuitive interface designed for job-site use • No internet connection required — works completely offline • No ads. No subscriptions. No data collection.

Ordinary calculators round. Constructive Calculator doesn't. It computes with constructive real numbers, an arbitrary-precision engine that keeps every result exact and hands you as many correct digits as you ask for. The rounding errors that quietly accumulate in ordinary calculators simply never happen. AS MANY DIGITS AS YOU WANT A pocket calculator stops at about 15 digits and rounds off the rest. Constructive Calculator keeps every result exact, so the digits a normal calculator throws away are still there. Swipe √2, π, or any answer to pull in tens, hundreds, or thousands more, computed on demand. SCIENTIFIC KEYPAD Trigonometry in degrees or radians and their inverses, exponentials and logarithms, powers and roots, factorials, percentages, the constants π and e, and the standard normal distribution, its CDF Φ and quantile Φ⁻¹, computed to the same arbitrary precision as everything else. BIG INTEGERS, IN FULL 52! (the number of ways to shuffle a deck) prints in full, all 68 of its digits, with no scientific-notation hand-waving. BUILT FOR CLARITY A running tape of recent calculations, locale-aware digit grouping, and copy at whatever precision you need. Constructive Calculator is an independent port of Hans Boehm's constructive-reals calculator, rebuilt natively for iPhone and iPad.