Free, Open-Source Electronics Calculators

30 professional-grade tools for engineers, students, and makers — from Ohm's Law to solar panel sizing.
IEEE-verified formulas. Instant results. No sign-up. Always free.

🌐 Live Demo · 📐 Calculators · 🚀 Get Started · 🤝 Contribute

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⭐ Star This Repo

If ElectroCalc helps you in your projects, coursework, or daily work — please give it a star! ⭐

It helps more engineers and students discover these free tools.

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📐 Calculators

Fundamentals

Calculator	Description
Ohm's Law	Voltage, current & resistance calculations
Current Divider	Parallel resistor current
Power Calculator	Power, voltage, current (P=VI)
Voltage Divider	Resistor divider circuit design
Star-Delta Conversion	Y ↔ Δ network transformations for 3-phase circuits
RC Time Constant	RC charging/discharging
Pull-up / Pull-down	Optimal resistor values for digital logic

Components

Calculator	Description
Resistor Color Code	Decode 4/5/6 band color codes
SMD Resistor Decoder	3/4 digit surface-mount markings
Capacitor Code	Numeric code to capacitance values
LED Series Resistor	Current-limiting resistor selection

Wire & Cable

Calculator	Description
AWG Wire Gauge	American Wire Gauge lookup with current ratings
SWG Wire Gauge	British/Indian Standard Wire Gauge

Power & Solar 🔋

Calculator	Description
Inverter Calculator	Inverter VA & battery bank sizing
Battery Backup Time	Runtime estimation from Ah & load
Battery Charging Time	Charge duration from capacity & charger
Inverter-Battery Matching	Right inverter + battery combo
AC Load Calculator	Home power, monthly kWh & ₹ cost
DC Load Calculator	Off-grid DC system sizing (12V/24V/48V)
Energy Calculator	Wh and kWh consumption
Solar Calculator	Panel, battery, charge controller & inverter sizing

AC & Signals 📡

Calculator	Description
AC Power Calculator	Active, Apparent, and Reactive Power
Real vs Reactive Power	Solve the AC Power Triangle
RMS Voltage Calculator	RMS, Peak, Peak-to-Peak, and Average
LC Resonant Frequency	Resonant frequency of LC circuit
Decibel (dB) Gain	Power & voltage gain in dB
Frequency & Wavelength	Convert Hz and meters
Duty Cycle Calculator	PWM signal parameters
Rise Time & Bandwidth	BW = 0.35 / tr
Period / Frequency	Convert Period and Frequency

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🛠️ Tech Stack

Technology	Version	Purpose
Next.js	16	React framework (App Router)
React	19	UI library
TypeScript	5.9	Type safety
Tailwind CSS	4	Utility-first styling
Lucide React	—	Icon library
Radix UI	—	Accessible UI primitives
KaTeX	—	Math formula rendering

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🚀 Getting Started

Prerequisites

• Node.js ≥ 18
• npm, yarn, pnpm, or bun

Installation

# 1. Clone the repo
git clone https://github.com/Saipreetham0/ElectroCalc.git
cd ElectroCalc

# 2. Install dependencies
npm install

# 3. Start dev server
npm run dev

Open http://localhost:3000 to see it running.

Build for Production

npm run build
npm start

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📁 Project Structure

ElectroCalc/
├── app/                          # Next.js App Router pages
│   ├── page.tsx                  # Homepage (SEO server component)
│   ├── HomePageClient.tsx        # Homepage client UI
│   ├── ohms-law-calculator/      # Each calculator has its own folder
│   │   ├── page.tsx              # SEO metadata
│   │   └── ClientPage.tsx        # Interactive calculator UI
│   ├── resistor-color-code-calculator/
│   ├── voltage-divider-calculator/
│   ├── solar-load-calculator/
│   └── ...                       # 30 calculator folders total
├── components/
│   ├── NavBar/                   # Navbar with mega dropdown
│   ├── Footer/                   # Footer with all links
│   ├── Theme/                    # Dark/light mode toggle
│   ├── ui/                       # Reusable UI components (shadcn)
│   └── ToolPageHeader.tsx        # Shared calculator page header
├── public/
│   ├── logo/                     # KSP Electronics logos
│   └── site.webmanifest          # PWA manifest
├── styles/
│   └── globals.css               # Global styles + Tailwind
└── package.json

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🤝 Contributing

We'd love your help making ElectroCalc better! Here's how you can contribute:

Ways to Contribute

• 🧮 Add a new calculator — Build a tool that helps electronics engineers
• 🐛 Fix bugs — Found something broken? Fix it!
• 🎨 Improve UI/UX — Make the experience better
• 📝 Improve documentation — Better docs help everyone
• 🌐 Add translations — Help us go multilingual
• ⚡ Optimize performance — Make it faster

How to Contribute

1. Fork the repository
2. Create a feature branch: git checkout -b feat/my-new-calculator
3. Make your changes
4. Test that TypeScript compiles: npx tsc --noEmit
5. Commit with a clear message: git commit -m "feat: add XYZ calculator"
6. Push to your fork: git push origin feat/my-new-calculator
7. Open a Pull Request

Adding a New Calculator

Each calculator follows this pattern:

app/your-calculator/
├── page.tsx           # Server component with SEO metadata
└── ClientPage.tsx     # "use client" — interactive calculator UI

1. Create the folder under app/
2. Add SEO metadata in page.tsx
3. Build the calculator UI in ClientPage.tsx
4. Register it in app/HomePageClient.tsx (calculators array)
5. Add it to the navbar in components/NavBar/index.tsx
6. Add it to the footer in components/Footer/index.tsx
7. Add it to the sitemap in app/sitemap.ts

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🌟 Join the Community

• ⭐ Star this repo to show your support
• 🍴 Fork it and build your own tools
• 🐛 Open issues for bugs or feature requests
• 💬 Discussions — share ideas and ask questions
• 📢 Share with fellow engineers and students

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📜 License

This project is open source and available under the MIT License.

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🔗 Links

	Link
🌐 Live App	tools.kspelectronics.in
🛒 Shop Components	kspelectronics.in
📺 YouTube	@kspelectronics0
💼 LinkedIn	KSP Electronics
📘 Facebook	kspelectronics.in

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Built with ❤️ by KSP Electronics
_{Telangana, India 🇮🇳}