# OP Calc — Oblique-Plane Calculator

> Oblique-Plane Calculator (iPhone/iPad app by Chu An Luo.)

- Source: https://appshunter.io/ios/app/op-calc/id6790341961 (this page in markdown: same URL + `.md`)
- Developer: [Chu An Luo](https://appshunter.io/developer/1257642394)
- Category: Medical, Health & Fitness
- Price: $0.99
- Age rating: 4+
- Requires: iOS 17.6 · 2 MB
- Languages: American English
- Released: 2026-07-21
- Data updated: 2026-07-26
- User reviews in markdown: https://appshunter.io/ios/app/op-calc/id6790341961/reviews.md

## What is OP Calc?

Oblique Plane Calculator is an offline angle-conversion utility. Enter sagittal (LAT) and coronal (AP) angles to calculate the oblique-plane angle (OBL) and the Alpha angle (the angle between the oblique plane and coronal plane).

Features
• Calculate OBL and Alpha angles from LAT and AP angulation
• Set left or right side and anterior/posterior and medial/lateral directions
• View a dynamic diagram of the OBL vector and Alpha angle
• Light and dark appearance
• No account, no data collection, and offline use


## Version history (last 1 release)

### 1.0 — 2026-07-21

No release notes.

## More apps by Chu An Luo

- [OsteoMaster](https://appshunter.io/ios/app/osteomaster/id1257642395)
- [OsteoGauge - lower limb](https://appshunter.io/ios/app/osteogauge-lower-limb/id1312951940)

All apps by Chu An Luo: https://appshunter.io/developer/1257642394

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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 2026-07-26.*