Comparison

Engineering Formulas vs Formulary+

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

Head to head
About

Engineering Formulas

Features
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EngiRef is the all-in-one engineering reference app that works 100% offline. Access formulas, material properties, reference tables, and a powerful unit converter - all without internet connection. FORMULA LIBRARY Browse 140+ essential engineering formulas organized by discipline: • Mechanical Engineering: stress, strain, torque, power, gear ratios, spring design • Electrical Engineering: Ohm's law, AC/DC circuits, impedance, resonance • Civil/Structural: beam deflection, Euler buckling, Manning's equation • Thermodynamics: ideal gas law, Carnot efficiency, heat transfer • Fluid Mechanics: Bernoulli, Reynolds number, Darcy-Weisbach • Materials Science: Young's modulus, Poisson's ratio, fatigue analysis BUILT-IN CALCULATOR Enter your values and get instant results. Every calculation shows step-by-step solutions so you understand the process, not just the answer. Perfect for learning and exam preparation. MATERIALS DATABASE Access properties for 55+ engineering materials: • Carbon steels (AISI 1018, 1045, 4140, 4340) • Stainless steels (304, 316, 17-4 PH) • Aluminum alloys (6061-T6, 7075-T6, 2024-T3) • Titanium, copper, nickel alloys • Plastics (ABS, HDPE, Nylon, PEEK, Delrin) • Composites, concrete, and wood Compare up to 3 materials side-by-side with density, tensile strength, elastic modulus, thermal conductivity, and more. REFERENCE TABLES • Bolt specifications: Metric M3-M36, SAE/Imperial sizes • Pipe schedules: NPS dimensions and wall thickness • Wire gauges: AWG 0000-40 with ampacity ratings UNIT CONVERTER Convert between 16 categories including length, pressure, temperature, force, energy, flow rate, and viscosity. Accessible from any screen via slide-over panel. PHYSICAL CONSTANTS Quick reference for 34 constants including speed of light, gravitational constant, Boltzmann constant, Avogadro's number, and more. QUIZ MODE Test your knowledge with flashcard-style quizzes. Track progress across all disciplines. Prepare for FE and PE exams. ADDITIONAL FEATURES • Dark and light themes (follows system setting) • Favorites to bookmark frequently used formulas • Calculation history with timestamps • Create and save custom formulas • Export and share your data • LaTeX formula rendering • iPad-optimized layouts PRIVACY FOCUSED EngiRef collects zero personal data. No analytics, no ads. All your calculations and favorites stay on your device. We believe engineering tools should respect your privacy. Whether you are a student preparing for exams, a working engineer needing quick field reference, or a technician looking for material specs, EngiRef puts essential engineering knowledge in your pocket. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Formulary+

Features
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Formulary+ is not another formula list. It is a complete computational reference — 4,727 formulas across 16 disciplines, each with an interactive solver, evaluator, or worked example that lets you compute, verify, and learn, not just look things up. Every equation is rendered in real-time LaTeX (KaTeX), not screenshots. Every variable is defined with its SI unit. And every formula you open is one you can actually use. WHAT MAKES IT DIFFERENT Interactive Solver — Pick any variable, enter the rest, get the answer with full step-by-step solution. Covers 1,500+ formulas across all 16 disciplines. Evaluator — For identities, bounds, and series: plug in numbers and see both sides computed side by side. You see not just that a claim holds, but by how much. Worked Examples — For complex equations (tensors, PDEs, procedures): a real computation with real numbers, showing every substitution step. Personal Notes — Write directly on any formula. Export all notes as Markdown — your work is never locked in. 4,727 FORMULAS · 16 DISCIPLINES · 150 SUBCATEGORIES Mathematics — 356 formulas Algebra · Calculus · Linear Algebra · Differential Equations · Statistics & Probability · Number Theory · Discrete Math Physics — 448 formulas Classical Mechanics · Thermodynamics · Electromagnetism · Optics · Waves · Quantum Mechanics · Relativity · Fluid Mechanics Chemistry — 241 formulas Stoichiometry · Thermochemistry · Kinetics · Equilibrium · Electrochemistry · Quantum Chemistry Geometry — 229 formulas Euclidean · Analytic · Differential · Topology Mechanical Engineering — 342 formulas Computer Science — 355 formulas Electrical Engineering — 319 formulas Civil Engineering — 343 formulas Biology & Biomedical — 203 formulas Environmental Engineering — 311 formulas Geological Engineering — 271 formulas Geochemistry — 204 formulas Geophysics — 215 formulas Chemical Engineering — 325 formulas Meteorology & Atmospheric Science — 296 formulas Astronomy & Astrophysics — 269 formulas BUILT FOR REAL WORK Real LaTeX rendering — KaTeX, not static images Full variable definitions with SI units Smart search across 4,727 entries Favorites — build your personal formula collection Related formulas — discover connected equations Share as LaTeX, plain text, or rendered image Export notes as Markdown Backup & restore your favorites and notes Dark mode · All iPhone & iPad sizes FREE TO TRY, FAIR TO BUY Browse the entire catalog for free — every category, every search result, every title. Open 5 formulas per day at no cost. Formulary Pro unlocks everything: Monthly — $1.99/mo Yearly — $19.99/yr (save 17%) Lifetime — $29.99 once, forever BUILT FOR Engineering students · Science undergrads · Graduate researchers · STEM professionals · Exam prep (PE, FE, GATE, GRE) · Teachers & professors · Anyone who works with equations Formulary Pro is an auto-renewable subscription. - Formulary Pro Monthly / Formulary Pro Yearly - Payment is charged to your Apple ID account at confirmation of purchase. - Subscription automatically renews unless canceled at least 24 hours before the end of the current period. - Manage or cancel in your Apple ID Account Settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://kingerders.github.io/formulary/privacy

Screenshots

Engineering Formulas4 screens
Formulary+4 screens

Verdict

The call

The clearest difference is iOS requirement: Engineering Formulas at 15.1 against Formulary+'s 17.0. On price, update cadence, ads and in-app purchases 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

Both are free to download. Engineering Formulas sells 3 in-app purchases, starting at $4.99 per 7 days and Formulary+ sells 10 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 4, 2026 and October 6, 2026 respectively.

Scorecard1 real difference · 5 level
Engineering Formulas versus Formulary+: the parameters behind the verdict, then further details
ParameterEngineering FormulasFormulary+
PriceFreeFree
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.1 — better17.0
Further details — not scored
Size45 MB17 MB
Age rating12+4+
DeveloperMobin AkhterERDINC ERSOY

In-app purchases

3 purchases

Engineering Formulas

Subscriptions2
  • Weekly Premium$4.997 Days
  • Yearly Premium$29.991 Year
One-time1
  • Lifetime Access$54.99
10 purchases

Formulary+

One-time10
  • Civil Engineering$0.99
  • Electrical Engineering$0.99
  • Geochemistry$0.99
Show 7 more
  • Meteorology & Atmospheric Science$0.99
  • Astronomy & Astrophysics$0.99
  • Chemical Engineering$0.99
  • Geophysics$0.99
  • Biology & Biomedical Engineering$0.99
  • Computer Science$0.99
  • All Disciplines Bundle$9.99

Questions

Is Engineering Formulas free?
Engineering Formulas is free to download, with in-app purchases available.
Is Formulary+ free?
Formulary+ is free to download, with in-app purchases available.
Do Engineering Formulas or Formulary+ have ads?
Neither Engineering Formulas nor Formulary+ shows ads.
Which is updated more often, Engineering Formulas or Formulary+?
Engineering Formulas ships an update every 2 months, and Formulary+ every 2 months. Most recently, Engineering Formulas was updated on October 4, 2026 and Formulary+ on October 6, 2026.

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