# Shakkan-hō Pro Converter — Shakkan-hō - Metric & Imperial

> Shakkan-hō - Metric & Imperial (iPhone/iPad app by Kyosuke Takahashi.)

- Source: https://appshunter.io/ios/app/shakkan/id6751975754 (this page in markdown: same URL + `.md`)
- Developer: [Kyosuke Takahashi](https://appshunter.io/developer/1393537221)
- Category: Utilities, Reference
- Price: Free
- Age rating: 4+
- Requires: iOS 11.0 · 37 MB
- Languages: Japanese
- Released: 2025-09-16
- Data updated: 2026-02-05
- User reviews in markdown: https://appshunter.io/ios/app/shakkan/id6751975754/reviews.md

## What is Shakkan?

Shakkan-hō Pro — Professional unit conversion & aggregation app

Overview
Shakkan-hō Pro instantly converts between Japan's traditional shakkan-hō units and modern metric or imperial systems. Ideal for stoneworkers, builders, surveyors, farmers, real estate professionals and traders who need accurate, work-ready conversions and totals.

Who it's for
• Stone industry — calculate sai (才) ⇄ cubic meters, cubic shaku volumes, and manage tombstone and stone block dimensions; sum multiple stone sizes for estimates.
• Construction & architecture — convert ken, shaku, sun for drawings and precise measurements; convert tsubo ⇄ square meters for area planning.
• Real estate — compute land area in tsubo, tan, se, chobu and present clear metric equivalents for listings and valuations.
• Agriculture & forestry — manage fields in tan/are/chobu for yield estimates and subsidy paperwork.
• Trade & export — convert pounds, yards, barrels, gallons between US/UK systems and metric.
• Jewelry & precious metals — monme ⇄ grams, carat conversions and metal weight calculations.

Key features

Comprehensive unit coverage
Length: ri, cho, jō, ken, shaku, sun, bu, rin, mō ⇄ km, m, cm, mm ⇄ mile, yd, ft, in
Area: chōbu, tan, se, tsubo, gō ⇄ km², ha, a, m² ⇄ acre, yd², ft²
Weight: kan, kin, monme, fun, rin ⇄ ton, kg, g ⇄ lb, oz, grain (carat supported)
Volume: koku, to, shō, gō, sai, cubic-shaku ⇄ m³, L, mL ⇄ bbl, gal, qt, pt

Aggregate calculator
• Auto-sum multiple conversion results (e.g., combine several stone blocks’ sai)
• Keep historical calculations for quick reference
• Calculate required order quantities for materials

Dimension-based volume calculations
• Enter length × width × height in shakkan-hō to get m³ and sai
• Ideal for stone, timber and material volume estimates

Professional accuracy
• Up to 6 decimal places for high-precision needs
• Scientific notation for very large/small values
• Reliable for professional use

Usability
• One-tap copy of results
• Three adjustable font sizes
• Dark mode
• Supports 10 languages (Japanese, English, Simplified/Traditional Chinese, Korean, Spanish, German, Italian, French, Arabic)

Other benefits
• Fully offline — no internet required
• Lightweight and responsive UI
• Clear conversion tables for quick checks
• Secure local data storage only (no cloud sync by default)

Recommended users
Architects, carpenters, stonemasons, real estate agents, farmers, exporters, gemologists, antiques appraisers, traditional craftsmen, land surveyors, construction consultants.

Shakkan-hō Pro brings Japan’s traditional measurement systems into modern workflows — precise, fast, and tailored for professionals.


## Version history (last 5 releases)

### 1.3.3 — 2025-10-01

Default unit set to mm
Remember user-selected units per page
On the volume page, change calculation from dimensions to length × width × height
When changing units in the total field, also append the record to the total history

### 1.3.0 — 2025-09-29

Added translations.  
Added units.  
Enabled unit selection when totaling.  
Made the total button clearer.  
Language is now selected automatically.  
Displayed history in all tabs.

### 1.1.9 — 2025-09-23

Make the total button easier to find.
Now automatically selects the language.
Show history on all tabs.

### 1.1.7 — 2025-09-22

Automatic language selection is now enabled.
History display on all tabs.
Translation within the history tab.

### 1.1.0 — 2025-09-19

Show history on all tabs.
Translation within the history tab.

## More apps by Kyosuke Takahashi

- [ジャグラーパチスロ設定判別＋Aメソッド](https://appshunter.io/ios/app/a/id1393537222)
- [レトロバトルロワイヤル](https://appshunter.io/ios/app/id1423554246)
- [島あげます～箱庭諸島～](https://appshunter.io/ios/app/id1434579636)
- [Aメソッド｜パチスロシミュ設定判別まとめ](https://appshunter.io/ios/app/a/id1445810988)
- [AmaOFF-RY](https://appshunter.io/ios/app/amaoff/id1527731821)
- [英検5級単語400 - 小学生向け英語学習 BUZZBEES](https://appshunter.io/ios/app/5400/id1535794462)

All apps by Kyosuke Takahashi: https://appshunter.io/developer/1393537221

## Related topics

[重量 平米](https://appshunter.io/ios/topics/)

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*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 2026-02-05.*