Comparison

Electrical Formulator vs Spindle Dynamics Studio

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

Head to head
About

Electrical Formulator

This app provides a comprehensive suite of electrical calculation tools for design and engineering challenges. It offers hundreds of conversion and calculation options, with features to save, print, and email results. Easily access frequently used and recently accessed formulas, with all calculations automatically stored.

Highlights
  • Over 100 electrical formulas
  • Save and organize results
  • Share results via email or print
  • Access most-used and recent formulas
  • Supports US/Imperial and metric units
  • Formula categories for batteries, motors, transformers, and more
Features
Read full description

Electrical Formulator: Your Complete Electrical Calculation Tool Solve virtually any electrical design or engineering challenge with this powerful and intuitive electrical formulator. Packed with hundreds of conversion and calculation tools, it’s the most versatile utility in your toolkit. Save, print, or email your results. Easily access your most-used and recently used formulas. Every calculation is automatically saved for future reference. Key Features: • Instant access to over 100 professional-grade electrical formulas • Save and organize your results for later reference • Share results via email or print • Highlights your most-used and recent formulas • Designed for engineers, electricians, and energy professionals Formula Categories: Batteries • Starting motor amperage • Number of cells required • Estimated operating time Cost Calculations • Appliance and lighting energy usage • Estimated usage hours for new bulbs • Insulation payback period BTU Conversions • BTU to joules, horsepower-hr, watt-hr, calories, foot-pounds, and more Generator Calculations • DC generator output • Generator amperage and efficiency Impedance & Reactance • Resistance & reactance combinations • Inductive and capacitive reactance • Total impedance and parallel circuits Kilowatts & Joules • Convert kilowatts to BTU/hr, joules/sec, lumens, horsepower, megajoules/hr, and more Motors • Single- and three-phase motor calculations • Locked rotor current • Motor kVA (including multiple input scenarios) • Motor speed analysis Ohm’s Law • Calculate for power, voltage, resistance, or current Transformers • Primary and secondary amperage • Full-load transformer sizing (208V, 240V, 480V for single and three-phase) • Impedance and amperage capacity calculations Voltage Drop • Copper and aluminum wire voltage drop (1-phase and 3-phase) • US/Imperial and metric units supported Wiring & Conduits • Wire size and resistance (copper and aluminum) • Wire length calculations • Conduit sizing Whether you’re working in the field, the lab, or the classroom, this electrical formulator helps you work faster, smarter, and with confidence. Users are able to calculate twelve formulas for FREE. Purchase a subscription to calculate additional formulas. All subscriptions come with a 1-WEEK FREE TRIAL and SUPPORT Family Sharing.

About

Spindle Dynamics Studio

Features
Read full description

The app is designed to perform Acceptance Testing for Industrial Spindles. Key Features: - Vibration Meter - Vibration Analysis Tools (Time-Waveform & Spectrum) - Spindle Vibration Acceptance Test - Spindle Thermal Testing - Spindle Single-Plane and Dual-Plane Balancing - Multisensor vibration test - Connects to commercial available wireless bluetooth sensors (no need to connect any cable to the iPad) - Data and Reports can be stored on the device or in the cloud for further analysis

Screenshots

Electrical Formulator4 screens

Verdict

The call

The clearest difference is in-app purchases: Spindle Dynamics Studio at none against Electrical Formulator's 1. Spindle Dynamics Studio also leads on iOS requirement (13.0 vs 18.4). On price, update cadence, ads 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

Both are free to download. Electrical Formulator sells 1 one-off in-app purchase. Spindle Dynamics Studio asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 23, 2026 and October 4, 2026 respectively.

Scorecard2 real differences · 8 level
Electrical Formulator versus Spindle Dynamics Studio: the parameters behind the verdict, then further details
ParameterElectrical FormulatorSpindle Dynamics Studio
PriceFreeFree
Rating5.0 (1 ratings) — better—
Positive reviews15.2% of reviews—
Number of ratings1 — better—
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPad — betteriPad
Requires iOS18.413.0 — better
Further details — not scored
Size16 MB107 MB
Age rating4+4+
DeveloperHistorycentral.comSens-OS

In-app purchases

1 purchases

Electrical Formulator

One-time1
  • Pro Features For Electrcial$1.99
None

Spindle Dynamics Studio

No in-app purchases

Questions

Is Electrical Formulator free?
Electrical Formulator is free to download, with in-app purchases available.
Is Spindle Dynamics Studio free?
Spindle Dynamics Studio is free to download, with no in-app purchases.
Do Electrical Formulator or Spindle Dynamics Studio have ads?
Neither Electrical Formulator nor Spindle Dynamics Studio shows ads.
Which is updated more often, Electrical Formulator or Spindle Dynamics Studio?
Electrical Formulator ships an update every 2 months, and Spindle Dynamics Studio every 2 months. Most recently, Electrical Formulator was updated on October 23, 2026 and Spindle Dynamics Studio on October 4, 2026.

Other comparisons