Vol. 12 · 246 tools, indexed · Updated daily
A complete
reference
for everyday
calculation,
from kilograms
to mortgages.
246 calculators and converters, arranged on a single page so you never click twice. Quiet typography, exact arithmetic, no advertising.
121
calculators
125
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 · ToolRound To The Nearest Ten CalculatorInstantly round any number to the nearest ten using the standard half-up formula. Supports positive numbers, negatives, and decimals.Open the tool№ 02 · ToolRound To The Nearest Tenth CalculatorRound any decimal to the nearest tenth instantly. Enter a number, choose a rounding method — half-up, half-down, or banker's rounding — and get accurate one-decimal-place results.Open the tool№ 03 · ToolRound To The Nearest Integer CalculatorRound any decimal to the nearest whole number instantly. Supports round half up, round half away from zero, and banker's rounding modes.Open the tool№ 04 · ToolCash Back CalculatorCalculate annual credit card cash back rewards across spending categories, sign-up bonuses, and annual fees to find the best card for any budget.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.