CurrentSpec: Electrical Calculators & Engineering Tools

Deterministic engineering tools for DC conductor sizing, voltage drop, circuit protection, lithium batteries, solar PV strings, and raceway mechanics.

FEATURED CALCULATOR

DC Conductor Sizing & Voltage Drop Calculator

Calculate DC wire size from your actual system voltage, load, cable length and voltage-drop target using a documented engineering reference basis.

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Quick Example Interactive Preview

System Voltage

Load Current

Cable Length

Voltage Drop Target

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Enter Values to Calculate

Enter system voltage, load current, cable length, and target drop above to see live sizing recommendations.

Popular Calculators

Quick access to our most used electrical calculators.

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Wire & Cable

DC Wire Size & Voltage Drop

Find the right wire size for your DC circuit based on voltage drop and ampacity.

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Wire & Cable

Exact DC Voltage Drop

Calculate exact voltage drop, loop resistance and power loss for custom lengths.

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Wire & Cable

Inverter Cable Sizing

Size cables for inverters based on power, efficiency and system voltage.

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Battery

Battery Bank Sizing

Calculate required capacity based on load, DoD and autonomy days.

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Solar

MPPT Controller Sizing

Match your solar array with an MPPT controller based on voltage and current.

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Wire & Cable

DC-DC Charger Cable Sizer

Size input and output cables for DC-DC chargers and auxiliary systems.

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Conduit & Thermal

Conduit Fill Calculator

Calculate raceway fill and minimum trade size per NEC guidelines.

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Advanced Energy

EV Charging Cable Sizer

Size high-voltage DC charging cables for EV systems and stations.

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Browse by Category

Explore all calculators in each engineering category.

Protection & Distribution

Battery & Energy Storage

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Practical Engineering Tools for Real-World Systems

These calculators use established engineering references (NEC, ABYC and industry standards) and provide accurate, transparent results based on your actual system values. Each tool includes assumptions, limitations and helpful guidance.

45+ Calculators

Across 9 categories

Engineering Reference & Standards Basis

Calculations are based on standard engineering physics and published electrical references. Voltage drop uses nominal uncoated-copper conductor resistance at 75°C (167°F) per National Electrical Code (NEC) Chapter 9, Table 8. Conductor ampacity references standard ABYC E-11 Table 6B (single conductor in free air with 105°C insulation) and NEC Table 310.16.

This utility is an educational and preliminary sizing reference. It is not system-specific engineering certification or a determination of code compliance. Overcurrent protection calculations explicitly distinguish the calculated sizing basis from final fuse or circuit breaker selection.