# SM Offset: Duct Calculator — Sheet metal & pipe offsets

> Offline offset calculator for sheet metal, HVAC, and pipefitting trades. (iPhone/iPad app by Bradley Evans.)

- Source: https://appshunter.io/ios/app/sm-offset-duct-calculator/id6781870096 (this page in markdown: same URL + `.md`)
- Developer: [Bradley Evans](https://appshunter.io/developer/6781870098)
- Category: Utilities, Productivity
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 15.0 · 6 MB
- Languages: American English
- Released: 2026-06-25
- Data updated: 2026-10-25
- Monetization: ad-supported

## What is SM Offset?

SM Offset is a field calculator for sheet metal workers, HVAC fabricators and pipefitters, built by a working sheet metal tradesman. Every calculator is free, it works with no signal, and answers come out in real tape-measure fractions.

ROUND
• Two-elbow offset: cut joint, travel and multiplier for a flat offset
• Rolling offset: rise and roll combined into one true offset, with the cut length to match

RECTANGULAR
• Radius elbows: two radius elbows plus a straight joint, with cut joint, travel and multiplier
• Mitered offset: square-throat elbows, with cheek length and miter setback
• Offset in a length: drop in the run you have, and the app works out the angle

TOOLS
• Duct resizer: something in the way? Shrink a side, keep the airflow
• Equivalent duct: round to rectangular and back (ASHRAE equal-friction and equal-area)
• Fraction ⇄ decimal, right triangle (any two values), arc length

SEND IT TO THE CREW
• Share any offset result as a text, with every size, angle and cut length

WHY TRADES TRUST IT
• Every offset is exact trig, cross-checked two independent ways
• A live drawing of the fitting as you type
• Fractions to 1/16" (or 1/32"), decimals, or metric
• Your shop's connection allowance, set once
• Recent calculations saved automatically
• Fast, dark, glove-friendly

Whether you're laying out ductwork in the shop or solving an offset on the roof, SM Offset gives you numbers you can cut to.

## Key features

- Two-elbow offset calculations
- Rolling offset calculations
- Duct fitting offsets
- Custom angle support
- Results in real fractions
- 100% offline functionality

## Is SM Offset safe?

Not enough ratings yet to assess SM Offset.

## Is SM Offset legit?

SM Offset: Duct Calculator appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for SM Offset is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Frequently asked questions about SM Offset

### What types of offsets can SM Offset calculate?

SM Offset calculates two-elbow offsets, rolling offsets, and duct fitting offsets. It provides cut length, arc lengths, elbow centerline, and total offset length for various scenarios.

### Does SM Offset work offline?

Yes, SM Offset is designed to work 100% offline, making it ideal for job sites with no signal.

### What devices does SM Offset support?

SM Offset is available for iPhone and iPod devices.

### What is the age rating for SM Offset?

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

### How often is SM Offset updated?

The latest version, 1.3.0, was released on September 28, 2026, indicating recent development and support.

### Does SM Offset have ads?

Yes, SM Offset contains advertisements.

### What is the user rating for SM Offset?

SM Offset has a perfect rating of 5.0 stars based on one review.

### What is the price of SM Offset?

SM Offset is available for free.

## Version history (last 5 releases)

### 1.4.0 — 2026-10-24

Send a result to a coworker: tap Share under any offset and it goes out as a text with every size and cut length.

Also new: a "Rate Offset" row in Settings. If Offset has saved you a trip to the brake, a rating helps other tradespeople find it.

### 1.3.0 — 2026-09-28

Patterns has been removed from Offset.

Also gone: the "Rolling Ninety" card on the Round screen. It was a placeholder,
not a calculator.

Every calculator is free and uncapped. A small banner ad at the bottom of the
screen is what pays for it. Ads are non-personalised: no tracking prompt, no
advertising identifier, and nothing you enter ever reaches an ad network.

### 1.2.2 — 2026-08-21

New: the Patterns section. Full-scale flat patterns for square-to-round
transitions — laid out, dimensioned, ready to mark and cut. Preview a worked
sample free; the Pro unlock (one purchase, no subscription, works offline) rolls
out shortly.

The free calculators stay free and stay uncapped. They now carry a banner at the
bottom of the screen, and Pro will remove it for good. A banner never blocks a
calculation — no signal, no banner, the tool just works.

### 1.2.1 — 2026-08-07

Fixes account deletion, which failed silently on the last version. Everything
else is unchanged.

### 1.2.0 — 2026-07-23

• Millimetres. The whole app now works in mm or inches — switch anytime in Settings.

• New fitting: Offset in a Length. A drawing gives you a drop and a length, never an angle — so this one works out the angle and the two brake lines for you.

• Cut lengths to mark on the metal. Pick your connection (S & drive, slip joint, Pittsburgh, and more) and every result also shows the length to actually cut, with the arithmetic spelled out so a wrong number is obvious.

• Duct Resizer rebuilt from the field duct-sizing chart, and it now handles duct up to 42".

• A new app icon.

• A few fixes and polish.

## Apps similar to SM Offset

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [FitterMaster: Pipe Fitter Calc](https://appshunter.io/ios/app/fittermaster-pipe-fitter-calc/id6790653655) | 5.0 (4) | Free | Utilities |
| [Transitions Layouts](https://appshunter.io/ios/app/transitions-layouts/id6757512792) | 5.0 (1) | Free | Utilities |
| [FabCalc: Flat Pattern DXF](https://appshunter.io/ios/app/fabcalc-flat-pattern-dxf/id6781708798) | — | Free | Utilities |
| [Sheet Metal Calculator Pro](https://appshunter.io/ios/app/sheet-metal-calculator-pro/id6753674123) | 4.3 (9) | Free | Utilities |
| [HVAC Calculator: BTU & AC Load](https://appshunter.io/ios/app/hvac-calculator-btu-and-ac-load/id6783446314) | — | Free | Utilities |
| [Duct Calculator Elite](https://appshunter.io/ios/app/duct-calculator-elite/id665701601) | 4.8 (234) | $9.99 | Utilities |

## More apps by Bradley Evans

- [Site Walk AI](https://appshunter.io/ios/app/site-walk-ai/id6797259122)
- [Foreman Walk](https://appshunter.io/ios/app/foreman-walk/id6802881821)

All apps by Bradley Evans: https://appshunter.io/developer/6781870098

## Related topics

[offset](https://appshunter.io/ios/topics/offset) · [easy offset](https://appshunter.io/ios/topics/easy-offset) · [offset calc app ansi](https://appshunter.io/ios/topics/offset-calc-app-ansi) · [offset calc app](https://appshunter.io/ios/topics/offset-calc-app) · [ductwork](https://appshunter.io/ios/topics/ductwork) · [rolling offset calculator](https://appshunter.io/ios/topics/rolling-offset-calculator) · [taper offset spacing calculato](https://appshunter.io/ios/topics/taper-offset-spacing-calculato) · [ogset](https://appshunter.io/ios/topics/ogset) · [easy pipe fitter](https://appshunter.io/ios/topics/easy-pipe-fitter) · [compound offset calculator](https://appshunter.io/ios/topics/compound-offset-calculator) · [ibend offsets](https://appshunter.io/ios/topics/ibend-offsets) · [duct](https://appshunter.io/ios/topics/duct) · [smacna greater chicago](https://appshunter.io/ios/topics/smacna-greater-chicago)

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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 2026-10-25.*