# ElbowCalc vs Duct Calc

The clearest difference is update cadence: Duct Calc at every 4 days against ElbowCalc's every 5 weeks. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. ElbowCalc sells 1 one-off in-app purchase and Duct Calc sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ElbowCalc ships an update every 5 weeks, Duct Calc every 4 days. The most recent releases landed on October 14, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | ElbowCalc | Duct Calc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (7 ratings)](https://appshunter.io/ios/app/elbowcalc-flat-pattern-maker/id6753796014/reviews)** | — |
| Number of ratings | **7** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 37 MB | 29 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | +4 | 4+ |
| Developer | [Sachinbhai Surani](https://appshunter.io/developer/1838685550) | [Gun woo Kim](https://appshunter.io/developer/1700263119) |

## What reviewers say

### ElbowCalc

[App page](https://appshunter.io/ios/app/elbowcalc-flat-pattern-maker/id6753796014)

This professional tool assists engineers and fabricators in quickly calculating and visualizing flat patterns for elbows and reducers. It provides instant pattern graphs with cut coordinates to streamline fabrication and minimize material waste.

**Highlights:** Calculate various elbow types, Generate flat pattern graphs, Supports reducer bends, Provides cut coordinates, Fast and precise calculations, Share and save results

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime premium | $19.99 | one-time |


### Duct Calc

[App page](https://appshunter.io/ios/app/duct-calc-hvac-duct-sizer/id6792500757)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Duct Calc Pro | $9.99 | one-time |


## Frequently asked questions

### Is ElbowCalc free?

ElbowCalc is free to download, with in-app purchases available.

### Is Duct Calc free?

Duct Calc is free to download, with in-app purchases available.

### Do ElbowCalc or Duct Calc have ads?

Neither ElbowCalc nor Duct Calc shows ads.

### Which is updated more often, ElbowCalc or Duct Calc?

ElbowCalc ships an update every 5 weeks, and Duct Calc every 4 days. Most recently, ElbowCalc was updated on October 14, 2026 and Duct Calc on October 13, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*