# ASHRAE 365 vs Ductulator

The clearest difference is review sentiment: Ductulator at 50% against ASHRAE 365's 0%. Ductulator also leads on rating (4.7 vs 4.2) and ratings volume (358 vs 10). ASHRAE 365's advantage is price (Free vs $3.99). On update cadence, ads, in-app purchases and device support there is nothing between them.

ASHRAE 365 is free to download; Ductulator costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Ductulator holds the better App Store score, 4.7 against 4.2. That said, the two scores are not equally well evidenced: Ductulator has 358 ratings behind it against 10, so its average is the more settled of the two. Written reviews point the same way: 0% of ASHRAE 365's written reviews are positive against 50% of Ductulator's.

ASHRAE 365 ships an update every 4 months, Ductulator every 2 months. The most recent releases landed on October 27, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | ASHRAE 365 | Ductulator |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | [4.2 (10 ratings)](https://appshunter.io/ios/app/ashrae-365/id1337759799/reviews) | **[4.7 (358 ratings)](https://appshunter.io/ios/app/ductulator-duct-sizing/id1474939475/reviews)** |
| Number of ratings | 10 | **358** |
| Positive reviews | 0.0% of reviews | **50.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Ad-supported | **Free** |
| Best chart rank | — | **#58** |
| Size | 53 MB | 1 MB |
| Requires iOS | **17.6** | 18.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [ASHRAE, Inc.](https://appshunter.io/developer/375374912) | [Wassim Murr](https://appshunter.io/developer/1474939474) |

## What reviewers say

### ASHRAE 365

[App page](https://appshunter.io/ios/app/ashrae-365/id1337759799)

Access ASHRAE information year-round. Stay updated on global conferences and events, connect with the community via social media, and discover resources to support the Society.

**Highlights:** Conference and event updates, Social media integration, Resource discovery, Society support information, Year-round access

**Features:** Vision Pro support

**In-app purchases:** none


### Ductulator

[App page](https://appshunter.io/ios/app/ductulator-duct-sizing/id1474939475)

**Currently charting:** #58 Top Paid · Productivity (US App Store)

Instantly calculate HVAC duct sizes based on airflow, friction rate, or velocity. This tool provides accurate duct dimensions in seconds without needing charts, supporting various duct types and units.

**Highlights:** Instant duct sizing, Friction rate or velocity calculation, Multiple valid duct dimensions, IP and SI units support, Detailed sizing mode, Rectangular, circular, and flexible ducts

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

**In-app purchases:** none

**What reviewers like**

- 👍 Very helpful for duct sizing
- 👍 Easy to use in the field
- 👍 Saves time
- 👍 Seamless imperial/metric transitions
- 👍 Excellent tool for duct design

**What reviewers complain about**

- 👎 App should be free
- 👎 Functionality is pointless for some needs
- 👎 Doesn't help with traditional residential HVAC duct sizing
- 👎 App is a scam
- 👎 Decimal point doesn't work

**Reported bugs**

- Decimal point doesn't work on calculator
- New flex option isn't working properly
- Friction rate can't be changed in the latest version
- Skips duct sizes (e.g., 24-26)

**Requested features**

- Ability to pick duct size and see CFM
- Include flat oval ducts
- Option to select round or square duct
- Ability to enter duct size and get CFM
- Option for flex duct


## Frequently asked questions

### Is ASHRAE 365 free?

ASHRAE 365 is free to download, with no in-app purchases.

### Is Ductulator free?

Ductulator costs $3.99, with no in-app purchases.

### Which has better reviews, ASHRAE 365 or Ductulator?

Ductulator is rated higher. ASHRAE 365 averages 4.2 out of 5 from 10 ratings, while Ductulator averages 4.7 from 358 ratings.

### Do ASHRAE 365 or Ductulator have ads?

Neither ASHRAE 365 nor Ductulator shows ads.

### Which is updated more often, ASHRAE 365 or Ductulator?

ASHRAE 365 ships an update every 4 months, and Ductulator every 2 months. Most recently, ASHRAE 365 was updated on October 27, 2026 and Ductulator on October 29, 2026.

---

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