# mmCalc — Calculate Crop Factor & More!

> Photography focal length and crop factor calculator for various sensor sizes. (iPhone/iPad app by Joe Scotto.)

- Source: https://appshunter.io/ios/app/mmcalc/id1378536055 (this page in markdown: same URL + `.md`)
- Developer: [Joe Scotto](https://appshunter.io/developer/1378536054)
- Category: Photo & Video, Reference
- Price: Free with in-app purchases
- Rating: 4.85/5 from 34 App Store ratings · 6 written reviews indexed
- Age rating: 4+
- Requires: iOS 8.0 · 15 MB
- Languages: English
- Released: 2018-07-06
- Data updated: 2026-06-10
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/mmcalc/id1378536055/reviews.md

## What is mmCalc?

mmCalc is a super simple photography focal length calculator. Simply input your focal length, sensor size, and max aperture and we'll give you what the 35mm equivalent is of that configuration. If the simple calculator doesn't suit your needs, we also offer calculators for crop factor based on sensor size and completely custom lens + sensor crop factor calculations.

mmCalc also provides calculations for medium format and large format sensor sizes.

## Key features

- 35mm equivalent focal length calculation
- Crop factor calculation
- Custom lens and sensor crop factor
- Medium format sensor support
- Large format sensor support

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Ad Removal | $1.99 | one-time |


## Recent user reviews (6 of 6)

All indexed reviews: https://appshunter.io/ios/app/mmcalc/id1378536055/reviews.md

### 5/5 — Tony

*2022-11-07*

Very useful app accurate easy to use .Brilliant Thanks

### 5/5 — As advertised - no more no less

*2020-06-26, version 1.3*

Works as intended

### 5/5 — Good Program

*2019-12-10, version 1.3*

Well written, easiest way to calculate sensor diagonals relative to the image circle out there.  Kudos to the author.

### 1/5 — Confused. Pay for less?

*2019-02-07*

The website works perfectly, and so did the free app until I paid to remove the adverts. Then pop up boxes with no selectable fields cripple it’s interaction- the app no longer functions as purposed. Real shame, it’s design from a concept and GUI perspective are fantastic. Please remedy.

### 5/5 — Love it!

*2018-10-02, version 1.3*

Really helped me out, definitely worth the download.

### 1/5 — Nothing happens!

*2018-06-09*

Not sure what this app is supposed to do but I input the information and nothing happens, I put in 90mm, f2.8 and the crop sensor at apsc and click.... nothing, no message, no window. I have no idea where I’m suppose to look to see the result. Oh well, in the trash it goes

## Frequently asked questions about mmCalc

### What is mmCalc used for?

mmCalc is a photography calculator that helps you determine the 35mm equivalent focal length of your lens based on your camera's sensor size. It also calculates crop factors and supports various sensor formats.

### What sensor sizes does mmCalc support?

mmCalc supports standard sensor sizes for calculating the 35mm equivalent focal length. It also specifically provides calculations for medium format and large format sensor sizes.

### Is mmCalc free to use?

Yes, mmCalc is available for free. It does not have any advertisements, making for an uninterrupted user experience.

### What devices can I use mmCalc on?

mmCalc is compatible with iPhone, iPad, and iPod devices. It is designed for iOS users.

### How accurate is mmCalc?

With a rating of 4.9 stars from 34 ratings, users have expressed high satisfaction with mmCalc's accuracy and utility in their photography workflow.

### When was mmCalc last updated?

The latest version of mmCalc, 1.3, was released on July 6, 2018. While not recently updated, its core functionality remains relevant for photographers.

### What is the age rating for mmCalc?

mmCalc has an age rating of 4+, indicating it is suitable for users of all ages and contains no mature content.

## Version history (last 4 releases)

### 1.3 — 2018-07-06

This app has been updated by Apple to display the Apple Watch app icon.

Fixed a bug where clicking "Show Lens Modifiers" would instantly open the teleconverter input.

### 1.2 — 2018-06-14

Added Lens Modifiers!

- Teleconverters
- Focal Reducers

Either select a preset on the 35mm equivalent calculator or input your own value with the custom calculator.

### 1.1 — 2018-06-07

Bug fixes and performance improvements.

### 1.0 — 2018-06-06

No release notes.

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## More apps by Joe Scotto

- [Reciprocitize](https://appshunter.io/ios/app/reciprocitize/id6736762955)

All apps by Joe Scotto: https://appshunter.io/developer/1378536054

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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 2026-06-10.*