Wire Size & Voltage Drop Calc
Stop testing wire gauges one by one! Automatically calculates commercial AWG & metric mm² sizes, breaker trip ratings (Ib ≤ In ≤ Iz), 8 conductor metals (Copper, Aluminum, Pure Nickel, Nichrome), AC Mains, 12V/24V/48V Solar, 40% Conduit Fill, and 40 Offline Guides.
✓ Free on Android • ✓ 100% Offline • ✓ Verified Calculations
⚡ Live Interactive Mini-Calculator: Voltage Drop & Joule Heat
Ohm's Law EngineTest conductor resistance (R = ρ·L/A) and see heat wasted in the cable before installation:
Joule Heat Loss in Cable: 157.5 Watts
Latest Field Guides & Technical Manuals
Why Residential AC Breakers Catch Fire on DC Solar Panels (Zero-Crossing Physics)
Never wire standard household AC circuit breakers into off-grid solar PV strings or 48V LiFePO4 battery banks. Understand DC arc plasma sustainment, polarity traps, and NEC DC-rated disconnects.
Read Full Guide & Calculator →
Pure Nickel vs. Nickel-Plated Steel: Sizing Strips for 18650 & LiFePO4 DIY Battery Packs
Spot-welding DIY 18650 or LiFePO4 lithium battery packs? Discover why cheap nickel-plated steel strips overheat, how to test for 99.6% pure nickel, and how to calculate ampacity and heat loss.
Read Full Guide & Calculator →
NEC (AWG) vs. IEC (mm²) Wire Sizing & Why Breakers Must Obey Ib ≤ In ≤ Iz
Discover why cables melt even when the circuit breaker doesn't trip, how long wire runs create hidden I²R heat losses, and how to size both American AWG and commercial Metric mm² conductors in one tap.
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The 40% Conduit Fill Rule: How to Size PVC, EMT & Flexible Conduit Without Jamming Wires
Master the 40% conduit fill rule for PVC, EMT, and flexible corrugated conduit. Learn why overcrowding wires causes thermal derating, cable damage, and code inspection failures.
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12V vs. 24V vs. 48V Solar Battery Wiring: How to Size Inverter Cables & Class-T Fuses Safely
Why a 3000W inverter on a 12V battery bank demands massive 4/0 AWG copper cables, how switching to 48V saves hundreds of dollars in copper, and how to pick the exact ANL, MEGA, or Class-T DC fuse.
Read Full Guide & Calculator →