Vol. 12 · 99 tools, indexed · Updated daily
A complete
reference
for everyday
calculation,
from kilograms
to mortgages.
99 calculators and converters, arranged on a single page so you never click twice. Quiet typography, exact arithmetic, no advertising.
91
calculators
8
converters
0
categories
In rotation today — Mortgage payment, BMI, Celsius ↔ Fahrenheit, Tip & split, Date difference, Compound interest, kg ↔ lb.
Editor's picks · Spring 2026
№ 01 · ToolInvolute Function CalculatorCalculate the involute function inv(α) = tan(α) - α for gear design, mechanical engineering, and differential geometry applications.Open the tool№ 02 · ToolLinear Feedback Shift Register (Lfsr) Period CalculatorCalculate Linear Feedback Shift Register maximum period (2^n-1), required bits for target period, and pseudo-random sequence properties.Open the tool№ 03 · ToolLuhn Algorithm CalculatorValidate or generate check digits for credit cards, NPI numbers, and other identification numbers using the Luhn mod 10 algorithm.Open the tool№ 04 · ToolPrisoner's Dilemma CalculatorCalculate cumulative scores for iterated Prisoner's Dilemma games using different strategies and customizable payoff values.Open the tool
From the editors
What we mean
by “exact”.
Every conversion on terican uses constants ratified by the Bureau International des Poids et Mesures, computed in arbitrary precision and rounded only at the moment of display.
Calculators are open source, audited annually, and accompanied by their formulas in plain language — because a calculator that hides its arithmetic is just a magic trick.