WireSizer vs Wire Size Calc

WireSizer is the fast, accurate, and easy-to-use DC wire size calculator for choosing the correct wire gauge every time. Simply select your DC voltage, current, and total circuit length with flips of your finger. No keyboard required. WireSizer instantly calculates the correct wire gauge for the Voltage Drop percentage you need. WireSizer is ideal for: • Boats and marine electrical systems • RVs, trucks, and cars • Radios and electronics • Solar power and battery-based DC systems • Any low-voltage DC system up to 60 VDC Suitable for both professionals and DIY users. WireSizer automatically calculates the minimum wire size required for your circuit (assuming copper wire), taking Voltage Drop into account for installation and temperature conditions. Results are checked against current-carrying capacity (ampacity) limits to prevent using unsafe undersized wire. Supported values: • Voltage up to 60 VDC • Current up to 500 amps • Total circuit length up to 600 feet or 200 meters • Voltage Drop 1 to 20 percent • AWG wire 18 gauge to 4/0, plus 250 & 300 kcmil • SAE wire 18 gauge to 4/0 • Metric wire 0.75 mm² to 150 mm² WireSizer allows you to fine-tune calculations based on real-world installation conditions: • Engine compartment or other high-temperature environments • Sheathed, bundled, or conduit-run wire • Wire insulation ratings from 60°C to 200°C WireSizer also includes a Materials List so you can record and review all of your wire selections in one place. WireSizer calculates DC wire sizes in accordance with ABYC E-11 (July 2025). For typical low-voltage DC circuits, results generally correspond with ISO 13297:2020. Results are a design aid; final wire selection and installation compliance remain the installer's responsibility. Number and decimal formatting will follow your device's regional and language settings. WireSizer works without an internet connection and contains no ads. Designed exclusively for DC circuits - not for use with AC circuits. Results are a design aid. Final wire selection and installation compliance remain the installer's responsibility. WireSizer will cost you less than the wire scraps you probably throw away at the end of the day.

NEC wire size calculator for electricians, apprentices, and electrical engineers. Determine the correct wire gauge (AWG/kcmil) for any circuit using official NEC 2023 ampacity tables and derating factors. Supports continuous and non-continuous loads, copper and aluminum conductors, 6 insulation types, and both conduit and free air installations. No internet required - works 100% offline on the job site. FEATURES: - Continuous and non-continuous load sizing (125% factor) - 5 voltage presets: 120V, 208V, 240V, 277V, 480V - Single-phase and three-phase support - Copper and aluminum conductors: 14 AWG through 2000 kcmil - AWG and mm² (metric) display toggle - 6 insulation types: THHN, THW, TW, XHHW-2, NM-B, USE-2 - Conduit and free air installation methods - Temperature correction factor (NEC 310.15(B)(1)) - Conduit fill adjustment factor (NEC 310.15(C)(1)) - Termination rating check (60°C / 75°C per NEC 110.14(C)) - Overcurrent protection sizing (NEC 240.4(D)) - Optional voltage drop check when distance is provided - PASS/FAIL indicator for quick compliance check NEC REFERENCES: - Table 310.16 - Ampacity in conduit/raceway - Table 310.17 - Ampacity in free air - Table 310.15(B)(1) - Temperature correction factors - Table 310.15(C)(1) - Conduit fill adjustment factors - NEC 110.14(C) - Termination temperature limits - NEC 240.4(D) - Small conductor overcurrent protection PRO FEATURES (one-time purchase): - No ads - Save calculation history - Export calculations as PDF reports - Dark theme support BUILT FOR THE JOB SITE: This app is designed by electricians, for electricians. Enter your circuit parameters, get the recommended wire size instantly - no complicated menus or unnecessary features. One-hand operation, instant results. HOW IT WORKS: 1. Enter load current in amps 2. Select load type (continuous or non-continuous) 3. Choose voltage, phase, conductor material, insulation type 4. Set installation method and ambient temperature 5. Get recommended wire size with full derating breakdown The calculator automatically applies: - 125% continuous load factor - Temperature correction for ambient conditions - Conduit fill adjustment for conductor count - Termination temperature limit verification - Standard breaker size selection PERFECT FOR: - Licensed electricians - Electrical apprentices - Electrical engineers and designers - Electrical contractors - NEC code exam preparation - Journeyman and master electrician exams OFFLINE & PRIVACY: - Works 100% offline - no internet needed - No account required - No data collection - Your calculations stay on your device Simplify your wire sizing on the job site.