# Curvature — Earth Curvature Calculator

> Comprehensive earth measurement calculator with mapping and research tools. (iPhone/iPad app by Steven Wilkinson.)

- Source: https://appshunter.io/ios/app/curvature/id1441050109 (this page in markdown: same URL + `.md`)
- Developer: [Steven Wilkinson](https://appshunter.io/developer/1441050108)
- Category: Utilities, Reference
- Price: $1.99
- Rating: 5.00/5 from 2 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 17.6 · 70 MB
- Languages: British English
- Released: 2018-11-08
- Data updated: 2026-07-05
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/curvature/id1441050109/reviews.md

## What is Curvature?

Curvature: The Ultimate Earth Measurement Toolkit
Built from the ground up. Literally.

Welcome to the all-new Curvature, the most comprehensive tool for exploring, calculating, and documenting earth measurements. We have completely redesigned the app experience—new code, a sleek modern layout, and powerful features designed for researchers, students, and enthusiasts alike.

Whether you are analyzing globe geometry or exploring flat earth models, Curvature provides the advanced formulation and high-precision tools you need to visualize the world around you.

What’s New in Curvature?

### Advanced Earth Calculators

The Curvature Calculator: Our flagship tool now uses advanced formulation for more accurate results. For the first time, see your calculations come to life with a graphic representation of the results.

Quick Horizon Calculator: Instantly find the distance to the horizon based on your height of eye.

Quick Curvature Drop: A streamlined tool for rapid drop-distance results.

Formula Transparency: Access a dedicated section showing the exact formulas used for both globe and flat earth models.

### Redesigned Mapping & POIs

Precision Tools: Utilize the new measurement ruler to calculate distances directly on the map.

Points of Interest (POI): Drop pins on key locations and save them for future reference.

Data Persistence: Powered by SwiftData, your saved measurements, POIs, and calculations are stored securely in organized folders on your device.

### The Knowledge Hub

Expanded PDF Library: A high-performance PDF viewer that allows you to organize research. Pro Feature: You can now import and store your own PDF documents directly within the app.

Categorized Links: An improved card-style layout for web resources. Add your own custom links and categorize them to build your personal research database.

Comprehensive Glossary: A deep dive into the terminology of both globe and flat earth models.

Geographical References: A library of data points and geographical milestones for quick fact-checking.

### All-in-One Utility

Universal Unit Converter: Seamlessly convert between Distance, Speed, Weight, Temperature, Area, Volume, and Time.

Save & Export: Keep a permanent record of your findings with the ability to save every calculation you perform.

Modern. Clean. Accurate. Curvature is more than just a calculator; it’s a portable research laboratory. By providing the tools to calculate "the drop" and visualize the results, we put the power of observation and mathematics in your pocket.

Download Curvature today and start measuring your world.

## Key features

- Advanced Earth Calculators
- Graphic Result Visualization
- Precision Mapping Tools
- Data Persistence with SwiftData
- Expanded PDF Library
- Universal Unit Converter
- Save & Export Calculations

## Chart rankings

- #192 in Top Paid · Utilities (US App Store)

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/curvature/id1441050109/reviews.md

### 5/5 — Real Science

*2022-11-16*

This app is extremely accurate and provides actual data instead of fairy tales. Our eyes can’t see curvature, only straight lines. It’s pretty fun to do experiments with it. I suggest using it over water. From San Mateo shore to Treasure Island is about 18 miles. With my telescope 4 feet above the water it says there is about 160 feet hidden behind the curve which means most of the island shouldn’t be visible. In reality through our telescope we could see the water splashing on the shore, so yeah… Real science.

**Developer response:** Thank you. I recently updated the app with lots of new features and accuracy and had a full design from the ground up. Please update and wish you all the best!

### 5/5 — Great Earth Curvature app

*2018-11-08*

Finally, been waiting for a decent Earth Curvature app, since there isn’t any others on the app store. Also love the zetetic astronomy pdf thats included, already used this near my home.
Great, easy to use map section too.

## Frequently asked questions about Curvature

### What is Curvature?

Curvature is a comprehensive utility app designed for calculating and visualizing earth measurements. It offers advanced tools for analyzing globe geometry and exploring flat earth models, with features like a curvature calculator, horizon calculator, and precision mapping.

### What are the key calculation tools in Curvature?

Curvature includes an advanced Earth Calculator for accurate results with graphic representation, a Quick Horizon Calculator to determine distance to the horizon based on height, and a Quick Curvature Drop tool for rapid drop-distance calculations.

### How does Curvature handle saved data?

Powered by SwiftData, Curvature ensures your saved measurements, Points of Interest (POIs), and calculations are stored securely and organized into folders directly on your device for easy access and persistence.

### Can I import my own research documents into Curvature?

Yes, Curvature features an expanded PDF library that allows you to import and store your own PDF documents directly within the app, in addition to organizing research materials and web resources.

### What unit conversions are supported by Curvature?

Curvature includes a Universal Unit Converter that seamlessly handles conversions for Distance, Speed, Weight, Temperature, Area, Volume, and Time, making it a versatile tool for various measurement needs.

### What is the price of Curvature?

Curvature is available for a one-time purchase of $1.99. This provides access to all its features without any ongoing subscription fees or additional in-app purchases.

### Does Curvature have ads?

No, Curvature does not contain advertisements. It is a paid application designed to offer an uninterrupted user experience for its measurement and research tools.

### How often is Curvature updated?

Curvature was last updated to Version 2.2 on March 6, 2026. While specific update frequency isn't detailed, the latest version indicates ongoing development and support for the application.

## Version history (last 4 releases)

### Version 2.2 — 2026-03-06

Changed app icon.
Changed deployment to iOS 17 and above.

### 2.0 — 2026-03-02

This whole app has been completely redesigned from the ground up (literally) - New code, new design, and new layout.

 - Redesigned map with measurement ruler and POI's both with save data persistence.
 - Redesigned earth curvature calculator with more detailed and accurate calculations using advanced formulation. 
 - Earth Curvature calculations now create a graphic representation of the results.
 - Earth curvature calculations can now be saved.
 - Added data persistence (local SwiftData) to save calculations, measurements and POI's are stored within a saved folder.
 - PDF Library with improved PDF viewer and ability to add your own PDF's.
 - Links library with improved card layout and categorisation and ability to add your own links.
 - Added a Quick Horizon Calculator.
 - Added a Quick Curvature Drop Calculator.
 - Added a Unit converter (with distance, Speed, Weight, Temperature, Area, Volume and time) conversions.
 - Added References data showing geographical data points.
 - Added Formulas data showing all formulation used in globe earth and flat earth models.
 - Added Glossary for globe earth and flat earth models.

### 1.5 — 2019-01-07

Only minor updates this time, but major updates to come in the future.

Current Updates:
1) New app icon
2) Changed app name (reduced to make it smaller)
3) Added apple 3D maps to choice of map styles
    - Use two fingers swiping upwards, to tilt map into 3D.
4) Minor cosmetic changes.
5) Small app optimisations.

### 1.0 — 2018-11-06

No release notes.

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## More apps by Steven Wilkinson

- [Neon Physics](https://appshunter.io/ios/app/neon-physics/id6760776904)
- [Hades: Workout & Run Trainer](https://appshunter.io/ios/app/hades-workout-and-run-trainer/id6783533996)

All apps by Steven Wilkinson: https://appshunter.io/developer/1441050108

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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 2026-07-05.*