Wire Size Calculator
Calculate the correct wire gauge (AWG/SWG) for your electrical load. Prevent overheating with proper wire sizing based on current and distance.
What is Wire Size Calculator?
This wire size calculator determines the correct wire gauge for your electrical installation based on current load, cable run length, acceptable voltage drop, and insulation type. Supports AWG (American), SWG (British/Indian), and metric sizing.
How to Use This Calculator
- Enter your Current Load, Cable Run (one-way), System Voltage, and other required values in the input fields
- Results are computed instantly as you enter or modify values — no need to click a button
- Review the computed output showing your wire size results with a detailed breakdown
- Apply the result to your planning or decision-making, and revisit when your inputs change
How Wire Size Calculator is Calculated
This calculator uses the formula: Area = (2 × ρ × L × I) / Max Drop. Where ρ = 0.0175 Ω·mm²/m (copper) ; L = One-way length ; I = Current ; Max Drop = V × Drop%. Wire size must handle current without excessive voltage drop. Standard sizes: 1, 1.5, 2.5, 4, 6, 10 mm². All calculations run entirely in your browser — no data is transmitted to any server.
Frequently Asked Questions
What wire size do I need for a 15A circuit?
For 15A at standard distances: 1.5 sq mm (16 AWG) copper for up to 15m run. For longer runs (30m+), use 2.5 sq mm (14 AWG) to keep voltage drop under 3%. Always size up if in doubt.
What is voltage drop and why does it matter?
Voltage drop is the loss of voltage through the wire due to resistance. Keep it under 3% for branch circuits and 5% total. Excessive drop causes dim lights, slow motors, and wasted energy as heat in the wire. Longer runs need thicker wire.
Related Calculators
Related Guides
Why This Tool Is Essential
Smart everyday decisions start with accurate calculations. Wire Size Calculator helps you make informed choices in daily life — from budgeting and shopping to planning and organizing. In India's fast-growing consumer economy, being financially and numerically literate gives you a real advantage. This tool is designed for simplicity and speed, giving you instant answers without any signup or data collection.
Key Features
- Instant Wire Size Calculator calculation with validated formulas
- Detailed step-by-step result breakdown
- Works offline as a Progressive Web App
- Completely free — no signup or data collection
- Mobile-friendly responsive design
- Save and share your results easily
Tips for Better Results
- 💡 Bookmark this calculator for quick daily use — it works offline too.
- 💡 Use the results to make informed comparisons before spending.
- 💡 Share results with family members for collaborative decision-making.
- 💡 Check back periodically as prices and rates change over time.
- 💡 Combine with related calculators for more comprehensive analysis.
Ideal Users
Budget-conscious consumers, families planning expenses, small business owners managing costs, and anyone making everyday financial decisions.
📚 Complete Guide Available
Want to learn more? Read our comprehensive guide with detailed explanations, real-world examples, expert analysis, and actionable tips.
Read: WiresizeNote: This calculator provides estimates for informational purposes only. Results may vary based on local conditions and individual circumstances.
Maintained by: Sagar Sahni, Calc Labz | Review: formula checks, worked examples, and periodic updates
Need a correction? Contact us with the calculator name, your inputs, and the issue you found.
Last updated: April 2026