Comparison

DuctChecker vs Triangle Calc A

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

DuctChecker

Easily calculate duct dimensions using various engineering methods like constant pressure, static pressure regain, total pressure, and velocity. This tool simplifies complex duct design calculations, typically found in flow diagrams or slide rules.

Highlights
  • Constant pressure method calculation
  • Static pressure regain method
  • Total pressure method
  • Velocity method
  • Duct dimension determination
  • Simplified duct design
Features
Read full description

To determine the size of the duct constant pressure method, static pressure regain method, total pressure method, velocity method. Generally uses constant pressure method. This constant pressure method is how to determine the duct dimensions using the same value per 1 m on all duct friction loss. Usually determined by flow diagrams or duct design for slide rules. You can easily determine the duct by using this program.

About

Triangle Calc A

Features
Read full description

The fastest way to solve Right Triangles. Triangle Calc A is a minimalist and specialized tool for anyone who needs instant, accurate right triangle calculations. Designed for speed and precision, it eliminates complex menus so you can focus on your work. Key Features: ■ Specialized for Right Triangles: Just enter two known values to solve the rest:  ・Two sides (Pythagorean theorem)  ・One side and one angle (Trigonometry) ■ Instant Results: Get all sides, angles, Area, and Perimeter immediately. ■ Minimalist Interface: No distractions. Open the app, enter your numbers, and get the answer in seconds. ■ Professional Precision: High-accuracy calculations for engineering, construction, and education. Perfect for: ■ Construction & Carpentry: Calculating pitches, slopes, and framing layouts. ■ Engineering: Quick geometric verification on-site. ■ Education: A reliable companion for trigonometry homework.

Screenshots

DuctChecker3 screens
Triangle Calc A3 screens

Verdict

The call

The clearest difference is update cadence: DuctChecker at every 4 months against Triangle Calc A's every 56 months. DuctChecker also leads on iOS requirement (15.0 vs 26.0). Triangle Calc A's advantage is price ($0.99 vs $6.99). On ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

DuctChecker costs $6.99 and Triangle Calc A $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

DuctChecker ships an update every 4 months, Triangle Calc A every 56 months. Both last shipped on October 8, 2026.

Scorecard3 real differences · 5 level
DuctChecker versus Triangle Calc A: the parameters behind the verdict, then further details
ParameterDuctCheckerTriangle Calc A
Price$6.99$0.99 — better
Positive reviews0.0% of reviews—
Update frequencyEvery 4 months — betterEvery 56 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better26.0
Further details — not scored
Size23 MB0 MB
Age rating4+4+
DeveloperAIR DESIGN, INC.kohei yamane

In-app purchases

None

DuctChecker

No in-app purchases

None

Triangle Calc A

No in-app purchases

Questions

Is DuctChecker free?
DuctChecker costs $6.99, with no in-app purchases.
Is Triangle Calc A free?
Triangle Calc A costs $0.99, with no in-app purchases.
Do DuctChecker or Triangle Calc A have ads?
Neither DuctChecker nor Triangle Calc A shows ads.
Which is updated more often, DuctChecker or Triangle Calc A?
DuctChecker ships an update every 4 months, and Triangle Calc A every 56 months. Most recently, DuctChecker was updated on October 8, 2026 and Triangle Calc A on October 8, 2026.

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