CSiUnits vs Mechanical Engineering Toolkit
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
CSiUnits
This application provides a comprehensive tool for converting units across various scientific disciplines and everyday needs. It offers over 70 conversion options, catering to professionals, students, and anyone requiring precise unit transformations.
- Multiple one-time conversion lists
- Conversions for lifestyle and science
- Over 70 conversion options
- Numeric value input
- Converted values to all possible units
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CSiUnits is an app that helps in conversion of units. Target Users: • Individuals who need simple to complex unit conversion • Engineers, consultants and various professionals • Students and faculty Key Features: • Multiple one time conversion list • Conversions for various lifestyle needs and branches of science • More than 70 conversions to choose from Key Input: • Numeric value to be converted • Selected primary unit Key Output: • Converted values to all possible units
Mechanical Engineering Toolkit
This utility app provides a comprehensive collection of engineering equations and formulas for students and professionals. Easily perform calculations by selecting a formula and inputting variables, with detailed instructions and reference material included.
- Engineering equations and formulas
- Mechanics of Material calculations
- Theory of Elasticity formulas
- Composite Material properties
- Reference material
- Variable input for calculations
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Mechanical Engineering Toolkit is a professional engineering calculator for students, researchers, and practicing engineers. Choose a formula, enter your variables, and get instant results — with calculation steps, formulas, diagrams, and unit conversions shown along the way. Switch between SI and Imperial units anytime, save favorites, and find the right tool fast with recommendations by major. Save your inputs as named projects, and export any result as text, image, CSV or PDF. Categories and tools: Mechanics of Material • Moments of inertia of plane areas • Force-displacement relation of a bar • Torsion formula and angle of twist • Flexure formula of a beam • Transverse shear stress • Deflections and slopes of cantilever and simple beams • Plane stress transformation and Mohr's circle • Principal stresses and planes • Spherical shell and thin-walled pressure vessel stresses • Buckling load of a column • Thermal deformation and stress • Combined loading • Bolted / riveted joints • Fatigue safety factor • Shaft power and torque Statics • Centroid of an area • Resultant of a force system • Beam reactions • 2D truss analysis Machine Design • Helical compression springs • Spur gear geometry and stresses • Shaft fatigue design (DE-Goodman) • Bearing L10 life • Belt and chain drives • Bolt preload / torque-tension • Fillet weld strength • Press / shrink-fit interference • Shaft critical speed (Dunkerley) • Beam natural frequency (five end conditions) • Torsional natural frequency (one or two rotors) Fluids & Thermal • Reynolds number and flow regime • Pipe pressure drop (Darcy-Weisbach with Colebrook) • Pump and fan power • Composite wall conduction • Fin efficiency • Heat exchanger sizing by LMTD Theory of Elasticity • Constitutive relation of linear elastic material • Stress/strain of linear elastic material Composite Material • Lamina and laminate stress/strain • Lamina engineering constants • Laminate plane and 3D properties • Rule of mixtures • Failure criteria (Tsai-Hill, Tsai-Wu) Reference Tables • Drill & tap chart (metric and imperial thread series) • ISO 286 fits & tolerances • Standard sections (AISC W, IPE, HEB) • Unit converter No account required. Works offline. Available in English, Chinese, German, French, and Japanese.
Screenshots
Verdict
The clearest difference is in-app purchases: CSiUnits at none against Mechanical Engineering Toolkit's 1. CSiUnits also leads on ads (none vs shown) and iOS requirement (9.0 vs 15.0). Mechanical Engineering Toolkit's advantage is update cadence (weekly vs monthly) and ratings volume (64 vs 4). On price, rating, review sentiment 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
Both are free to download. Mechanical Engineering Toolkit sells 1 one-off in-app purchase. CSiUnits asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.8 for CSiUnits against 4.8 for Mechanical Engineering Toolkit. That said, the two scores are not equally well evidenced: Mechanical Engineering Toolkit has 64 ratings behind it against 4, so its average is the more settled of the two. Written reviews are what separate them: 50% of CSiUnits's written reviews are positive against 57% of Mechanical Engineering Toolkit's.
CSiUnits ships an update monthly, Mechanical Engineering Toolkit weekly. The most recent releases landed on September 17, 2026 and October 10, 2026 respectively.
| Parameter | CSiUnits | Mechanical Engineering Toolkit |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (4 ratings) | 4.8 (64 ratings) |
| Positive reviews | 50.0% of reviews | 57.1% of reviews — better |
| Number of ratings | 4 | 64 — better |
| Update frequency | Monthly | Weekly — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 9.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 13 MB | 40 MB |
| Age rating | 4+ | 4+ |
| Developer | Computers and Structures, Inc. | APPS BAY LIMITED |
Customer experience
CSiUnits
Mechanical Engineering Toolkit
In-app purchases
CSiUnits
No in-app purchases
Mechanical Engineering Toolkit
- Remove Ads$2.99
Questions
Is CSiUnits free?
Is Mechanical Engineering Toolkit free?
Which has better reviews, CSiUnits or Mechanical Engineering Toolkit?
Do CSiUnits or Mechanical Engineering Toolkit have ads?
Which is updated more often, CSiUnits or Mechanical Engineering Toolkit?
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