# TeleCalc — Optical calculations

> Telescope optical calculation tool for amateur and professional astronomers. (iPhone/iPad app by Fabio Rendelucci.)

- Source: https://appshunter.io/ios/app/telecalc/id413263665 (this page in markdown: same URL + `.md`)
- Developer: [Fabio Rendelucci](https://appshunter.io/developer/410590236)
- Category: Utilities, Education
- Price: $0.99
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: English, French, German, Italian, Japanese, Portuguese, Russian, Chinese, Spanish
- Released: 2011-01-18
- Data updated: 2026-06-10
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/telecalc/id413263665/reviews.md

## What is TeleCalc?

TeleCalc is an application that performs calculations on the optical characteristics for a telescope when its is  bound with a particular ocular lens, making easier for the astronomer amateur or professional to choose an equipment.

Given the equipment characteristics, calculates:

- Focal length
- Magnification
- Minimum magnification
- Maximum magnification
- Exit pupil
- Focal length of eyepiece
- Surface brightness
- Dawes resolution
- Rayleight resolution
- Pratical resolution
- Limiting magnitude
- Light gathering power
- Sharpness size of FOV
- Diffraction limit

Developed for iOS 17 or higher. Available in Portuguese, English, Spanish, French, German, Italian, Russian, Japanese and Simplified Chinese.

## Key features

- Focal length calculation
- Magnification metrics
- Exit pupil calculation
- Resolution analysis
- Light gathering power
- Field of view calculations

## Recent user reviews (3 of 3)

All indexed reviews: https://appshunter.io/ios/app/telecalc/id413263665/reviews.md

### 1/5 — Garbage

*2013-02-25*

Save your money. Looks useful but crashes. Limited results.

**Developer response:** We checked the program and did not detect any "crash". If possible, contact us by email indicating in what situation this occurred. We appreciate the feedback and apologize for the inconvenience.

### 1/5 — Do Not Buy

*2011-01-25*

DO NOT purchase this ap. It doesn't calculate properly. What a waste of money, and no thanks to Universe Today for their recommendation.

**Developer response:** We checked and updated the calculations in the new version. If possible, contact us by email indicating which of the calculations had an error. We appreciate the feedback and apologize for the inconvenience.

### 2/5 — Needs a Lot of Work

*2011-01-25, version 1.0*

Error messages on entry work poorly.

The keyboard covers the entry feilds! (that is boneheaded).

Should have things like sampling calculations for CCD imagers.

**Developer response:** We updated the layout and corrected the reported problems. We appreciate the feedback and apologize for the inconvenience.

## Frequently asked questions about TeleCalc

### What calculations does TeleCalc perform?

TeleCalc calculates various optical characteristics for telescopes, including focal length, magnification, resolution, exit pupil, surface brightness, and light gathering power.

### What devices is TeleCalc compatible with?

TeleCalc is developed for iOS 17 or higher and is available on iPhone and iPad.

### How much does TeleCalc cost?

TeleCalc is a paid application priced at $0.99.

### What languages does TeleCalc support?

TeleCalc is available in Portuguese, English, Spanish, French, German, Italian, Russian, Japanese, and Simplified Chinese.

### Is TeleCalc suitable for beginners?

Yes, TeleCalc is designed to make optical calculations easier for both amateur and professional astronomers, aiding in equipment selection.

### How often is TeleCalc updated?

TeleCalc was last updated on February 13, 2024, with version 7.0, indicating regular maintenance and potential feature additions.

### What is the age rating for TeleCalc?

TeleCalc has an age rating of 4+, making it suitable for a wide range of users.

### Does TeleCalc have ads?

No, TeleCalc does not contain advertisements.

## Version history (last 5 releases)

### 7.0 — 2024-02-13

New layout and greater precision in calculations.

### 6.2 — 2020-06-22

Correct the input error with decimal values ​​and incorporate seven new languages.

### 6 — 2019-11-06

Layout improvements

### 5 — 2019-11-04

New features, less inputs.

### 4 — 2013-01-04

Correct some errors. Enhance memory management.

## Apps similar to TeleCalc

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [BatteryPro++](https://appshunter.io/ios/app/batterypro-plus-plus/id1471763700) | 4.7 (239) | $2.99 | Utilities |
| [Catálogo Messier](https://appshunter.io/ios/app/catalogo-messier/id6443842540) | — | Free | Utilities |
| [Sunstone Batteriemonitor](https://appshunter.io/ios/app/sunstone-batteriemonitor/id1561341696) | — | Free | Utilities |
| [calc-o-scope](https://appshunter.io/ios/app/calc-o-scope/id1559076934) | — | Free | Utilities |
| [CableApp](https://appshunter.io/ios/app/cableapp/id1180099775) | 3.0 (2) | Free | Utilities |
| [S-Miles Installer](https://appshunter.io/ios/app/s-miles-installer/id1544207772) | 4.2 (991) | Free | Utilities |

## More apps by Fabio Rendelucci

- [LunarCalc](https://appshunter.io/ios/app/lunarcalc/id410590233)
- [EasterDate](https://appshunter.io/ios/app/easterdate/id415940926)
- [Resistor CC](https://appshunter.io/ios/app/resistor-cc/id445510576)
- [SideralClock](https://appshunter.io/ios/app/sideralclock/id460828053)
- [QSO](https://appshunter.io/ios/app/qso/id462025640)

All apps by Fabio Rendelucci: https://appshunter.io/developer/410590236

---

*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 2026-06-10.*