# Dozenal Calc — A calculator in base twelve > A calculator in base twelve (iPhone/iPad app by Eric Naville.) - Source: https://appshunter.io/ios/app/dozenal-calc/id6777149196 (this page in markdown: same URL + `.md`) - Developer: [Eric Naville](https://appshunter.io/developer/6777149198) - Category: Education, Utilities - Price: Free - Age rating: 4+ - Requires: iOS 13.0 · 32 MB - Languages: American English - Released: 2026-06-06 - Data updated: 2026-06-19 - User reviews in markdown: https://appshunter.io/ios/app/dozenal-calc/id6777149196/reviews.md ## What is Dozenal Calc? 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 ## Version history (last 4 releases) ### 1.5.1 — 2026-06-14 New in 1.5.1: • The unit converter is now the calculator's second page — just swipe left. Results travel between the two calculators at the press of a key. • Do math right inside the converter: × ÷ ⊕ ^ √ log, with memory and constants. • Color code: green for the world of ten (metric, base 10), violet for the world of twelve (imperial, base 12). • Two illustrated manuals and calculator recommendations — in 14 languages. • Optional light theme and a new settings page. Still no network, no trackers, no data collection. ### 1.3.0 — 2026-06-10 New in 1.3.0: Dozenal Calc is now also available for Mac and Apple Watch. • Mac: the full app as a native window – wide keypad, exact fraction arithmetic, all teaching chapters. • Apple Watch: a fast base-twelve calculator on your wrist – the twelve dozenal glyphs, basic operations, power, root and logarithm. Still no network, no trackers, no data collection. ### 1.2.0 — 2026-06-09 • Expanded theory: many chapters now feature public-domain historical illustrations — with tappable source credits. • Two related dozenal calculators linked (app and web), with a direct link. • New in the angle converter: slope as a percentage (0–90°). • Tables now align cleanly (a true monospace font). • Refined unit converter: clearer mode indicator and navigation. Still no network, no trackers, no data collection. ### 1.1.0 (14) — 2026-06-06 No release notes. ## Related topics [dozenal calc](https://appshunter.io/ios/topics/dozenal-calc) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-19.*