# Dozenal Calc

> A calculator in base twelve

Canonical page: [https://chrome-stats.com/d/id6777149196](https://chrome-stats.com/d/id6777149196)

## Overview

- **ID:** `id6777149196`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Eric Naville
- **Category:** Education
- **Version:** 1.5.1
- **Last updated:** 2026-06-14
- **First published:** 2026-06-06
- **Size:** 32 MB
- **Data as of:** 2026-09-26
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/dozenal-calc/id6777149196)
- **Privacy policy:** [https://dozenal.weltanschauung.app/privacy.de.html](https://dozenal.weltanschauung.app/privacy.de.html)

## Description

A "dozenal calculator" with a novel notation for numbers.

A "dozenal calculator" — a scientific calculator that computes not in tens, but in twelves. With its own symbols for the digits.

What base 12 can do that base 10 can't

In the decimal system, 1/3 is an infinite repeating fraction (0.333…). In base 12 it's short and exact: 0.4. Sixths, ninths, and every fraction whose denominator is built from twos and threes also become finite in dozenal. No coincidence: twelve has six divisors, ten only four.

Dozenal Calc computes exactly — a rational track runs in parallel with floating-point arithmetic. Repeating fractions appear with a bar over the recurring digits, for example 1/7 as 0.186A3 with a repetend bar.

Features

• Basic arithmetic, parentheses, signs
• Power, square root, nth root, logarithm to any base
• Trigonometric and hyperbolic functions including their inverses
• Constants π, e, φ, √2; factorial, absolute value, reciprocal, modulo
• Parallel addition (a⊕b) for resistor circuits
• Memory (STO/RCL/MC) with exact rational preservation
• Angle modes DEG / RAD / GRAD
• Numeral-system switch (base 12/10) in the settings — input AND result, applies to both calculators
• Light and dark theme

Unit converter

One swipe to the left opens the second calculator: it converts imperial and metric units into one another — length, area, volume, weight, time, angle, money (£/sh/d), temperature and more. Compound entries like 3 ft 5 in, breakdown into part units, and math right inside the entry (× ÷ ⊕ ^ √ log) with memory and constants. Results travel between the two calculators at the press of a key. A color code keeps the worlds apart: green for the world of ten (metric, base 10), violet for the world of twelve (imperial, base 12).

Hands-on theory — now with pictures

A richly illustrated read explains why twelve in particular is a special number, in three blocks:
• Twelve and the World — from the dodecagon and dodecahedron through pyrite, garnet, viruses and quasicrystals to music, art, architecture and calendars
• Dozenal Mathematics — divisors and periods, the number bases compared, a history of place-value systems
• Dozenal Society — the movement for twelve, new digits for ten and eleven, the TGM measurement system and related dozenal calculators

Many chapters show public-domain historical illustrations — from Haüy's pyrite plate through Leonardo's dodecahedron to Vermeer's balance — each with a tappable source citation. Plus a dedicated unit theory on measure and number, two illustrated operating manuals for both calculators, and recommendations for dozenal-friendly calculators on every platform.

Fourteen languages

Deutsch, English, Français, Español, Italiano, فارسی, Русский, Gaeilge, हिन्दी, 简体中文, 繁體中文, Cymraeg, 日本語, العربية — freely selectable in the info menu.

What Dozenal Calc doesn't do

• No ads, no tracking, no analytics
• No internet connection, no permissions
• No personal data

The app works completely offline. What you type stays on your device.

Who is it for?

For teachers who want to show how a different number system transforms everyday work with fractions — and for anyone who wants to see mathematics from an unfamiliar perspective.

License: MIT. Contact: dozenal@weltanschauung.app

## Rankings

- #1,370,314 — Overall

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Source: [Chrome-Stats](https://chrome-stats.com/d/id6777149196)