GridCalc Pro
Voltage Drop & EV Feeder Calc
$2.99 · Designed for iPad. Not verified for macOS.
Calculate power, voltage drop, transformers, CT/PT ratios, and power-factor correction offline—with visible formulas, warnings, saved work, and PDF reports.
GridCalc Pro is an offline electrical calculation workspace for engineers, electricians, designers, and commissioning teams.
Calculate and review:
• EV charging feeder comparisons and cable screening using your sourced conductor parameters
• Three-phase power, current, and voltage
• Voltage drop with AWG, kcmil, or mm² conductor input
• Transformer load and capacity conversions
• CT and PT nameplate ratios with safety warnings
• Power-factor correction
• Electrical and engineering unit conversions
• PV string/inverter and battery/PCS nameplate pre-checks
Built for work that must be revisited:
• See formulas, intermediate steps, assumptions, and warnings
• Save calculations to favorites, history, and projects
• Search saved work by title, project, values, source, warning, or formula context
• Restore the original inputs instead of keeping only a final number
• Export calculation context and results as PDF
• Work without an account or internet connection
• Use English, Simplified Chinese, or Spanish
• Send supported summaries to a paired Apple Watch
GridCalc Pro bundles no licensed NEC tables. Create a local custom cable pack or import compatible JSON; user-supplied values remain visibly unverified in results, saved records, and PDFs. Built-in values are marked as example data. A calculation report documents inputs and results; it is not engineering approval, a design stamp, inspection acceptance, or a guarantee of code compliance. Always verify real work against the adopted code, authority having jurisdiction, approved drawings, installation conditions, equipment listings, manufacturer instructions, and a qualified professional's review.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
• Calculate stays pinned above the keyboard, and each result scrolls into view with a confirmation.
• Long explanations and warnings collapse to a short preview you can expand; nothing is removed.
• Calculators are grouped and searchable (try “VD”, “xfmr”, or “EVSE”), and the app reopens where you left off.
• Common voltage shortcuts on Power, Voltage Drop, and Cable Sizing.
• Preview & Share any PDF report for AirDrop, Mail, Messages, or printing.
• Siri and Spotlight shortcuts open a calculator directly.
• Still fully offline, with no account or tracking. Built-in values remain example data, and your own cable parameters stay marked as unverified.
The developer, 响育 陈, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- 响育 陈
- Size
- 7.7 MB
- Category
- Productivity
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later. - Apple Watch
Requires watchOS 10.0 or later.
- iPhone
- Languages
English and 2 more
- English, Simplified Chinese, Spanish
- Age Rating
4+
- 4+
- Copyright
- © 2026 Xiangyu Chen
