Shakkan-hō Pro Converter
Shakkan-hō - Metric & Imperial
Free · Designed for iPad
Convert Japanese shakkan-hō to metric and imperial units instantly—area, volume, and weight. A professional tool for builders, stonemasons, and farmers.
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.
Ratings & Reviews
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
The developer, Kyosuke Takahashi, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Location
- Identifiers
- Usage Data
Data Linked to You
The following data may be collected and linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Kyosuke Takahashi
- Size
- 38.8 MB
- Category
- Utilities
- Compatibility
Requires iOS 11.0 or later.
- iPhone
Requires iOS 11.0 or later. - iPad
Requires iPadOS 11.0 or later. - iPod touch
Requires iOS 11.0 or later. - Mac
Requires macOS 11.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- Languages
- Japanese
- Age Rating
4+
- 4+
- Contains
Advertising
- Copyright
- © 2025 Kiyosuke (Kyosuke Takahashi)