Electrical Calculators
Code-compliant calculators for voltage drop, conduit fill limits, breaker sizing, OHM's law, and AWG references.
3 Phase Voltage Imbalance
Calculate NEMA voltage imbalances across 3-phase legs to determine the mandatory motor load derating factor required to prevent thermal stator failure.
Ac Motor Speed Slip
Calculate the theoretical synchronous speed of an AC induction motor and its operating slip percentage. Diagnose overloaded motors and optimize VFD frequency settings.
NEC Wire Ampacity Derating Calculator
Automatically calculate NEC 310.15 wire derating limits based on extreme ambient temperatures and excessive conduit fill (bundle crowding).
Available Fault Current & AIC Rating Calculator — NEC 110.24
Calculate available short-circuit fault current and verify equipment AIC ratings from utility transformer to branch panels using IEEE point-to-point impedance mathematics.
Battery Room Hydrogen Ventilation Calculator
Calculate minimum required exhaust airflow (CFM/L/s) to maintain safe hydrogen concentrations (below 1.0% by volume / 25% LEL) in lead-acid UPS battery rooms per IEEE 484 and IFC 1206.
Box Fill
Determine minimum required electrical box volume per NEC 314.16, including AWG conductor volumes, device double-count rules, equipment grounding conductor allowances, and clamp rules.
Cable Pulling Lubricant Estimator
Estimate how much cable pulling lubricant a conduit run needs from conduit length and inside diameter using the lubricant-industry rule of thumb Q = 0.0015 x L x D, with a +50% figure for difficult pulls.
NEC Cable Tray Sizing Calculator
Calculate required cable tray width per NEC Article 392 using the 50% fill ratio rule. Enter cable ODs and quantities to get minimum tray cross-section area and recommended standard tray width (6", 12", 18", 24", 30", 36") for multi-conductor power and control cable installations.
NEC Circuit Load & Breaker Sizing
Calculate total circuit amperage and determine the safe NEC breaker size required to handle both continuous and peak non-continuous loads.
Conduit 3-Bend Saddle Planner
Generate exact tape measure marks for a 3-bend electrical saddle. Calculate shrink amounts, center marks, and outside bend distances for 30-degree, 45-degree, and 60-degree saddles.
NEC Conduit Fill & Jam Ratio Capacity
Calculate conduit wire fill percentages against NEC guidelines and analyze 3-wire jam ratios to prevent cable pulling issues.
Conduit Nipple Fill (NEC 60%) Capacity
Mathematically calculate NEC Chapter 9 Note 4 wire fill limits for conduit nipples. Automatically override the 40% rule and apply the strict 60% mechanical threshold when runs are under 24 inches.
Conduit Offset Bend Calculator - Multiplier and Shrink
Calculate the distance between bend marks and the estimated shrink for a two-bend conduit offset at 10, 22.5, 30, 45 or 60 degrees using standard field multipliers and shrink factors.
Conduit Pull Tension
Calculate maximum conduit pull tension to prevent insulation damage during wire installation.
NEC Conduit Support Spacing Limits
Determine mandatory maximum strap support spacing for EMT, Rigid, and PVC conduit according to strict NFPA 70 National Electrical Code standards.
Data Center PUE & DCiE Diagnostics
Determine Power Usage Effectiveness (PUE) and Data Center Infrastructure Efficiency (DCiE) to calculate exact electrical cooling overhead and wasted facility compute ratios.
DC Voltage Drop Calculator for 12 V, 24 V and 48 V Circuits
Calculate two-wire DC voltage drop, percent drop and voltage at the load for copper conductors from 14 AWG to 4/0 using NEC Chapter 9 Table 8 resistance, with ABYC E-11 3% and 10% reference flags.
Solar DC Ampacity & Wire Sizing Limiters
Mathematically determine the exact AWG copper wire gauge required for off-grid solar and low-voltage DC battery banks. Calculate Circular Mils to prevent excessive voltage drop and conductor thermal rise.
Commercial EV Charging Service Load Calculator — NEC 220.87 & 625
Calculate commercial electrical service capacity, transformer headroom, and feeder sizing for EV charging stations under NEC 2023 Article 220.87 and 625.42 EVEMS.
AC Single-Phase Voltage Drop Calculator
Calculate conductor voltage drop for single-phase AC circuits using standard NEC Circular-Mil formulas (K=12.9 Copper / 21.2 Aluminum) and verify the 3% branch circuit guideline.
Available Fault Current & AIC Rating Calculator
Calculate transformer-terminal symmetrically bolted fault current (SCA) and minimum breaker AIC rating requirements. NEC 110.9 compliance engine using the impedance multiplier method.
Grounding Electrode Conductor (GEC) Sizing - NEC Table 250.66
Look up the minimum copper or aluminum grounding electrode conductor size from the largest service-entrance conductor using NEC 2023 Table 250.66, with the 250.66(A) to (C) electrode-specific limits.
Generator Gas Pipe Sizing Calculator (NG & LP)
Select the minimum required schedule 40 black iron gas pipe diameter for standby generators based on total BTUH demand and measured run length. Avoid generator fuel starvation and pressure drops during startup surges.
Backup Generator Sizing & Load Calculator
Determine exactly what size standby or portable generator you need. Calculate continuous running watts and single-motor surge startup watts for your essential household appliances.
Ground Fault Loop Impedance Calculator (Zs)
Calculate total Earth Fault Loop Impedance (Zs) to verify circuit safety compliance. Determine if fault currents are high enough to trip breakers within the mandatory 0.4-second window.
NEC Grounding Electrode Conductor Size Calculator
Determine the exact AWG / kcmil gauge requirement for main service Grounding Electrode Conductors (GEC) based on National Electrical Code Table 250.66.
IEEE 1584 Arc Flash Incident Energy & Fault Current
Calculate arcing fault current for electrical arc flash hazard analysis in low-voltage systems per IEEE 1584-2018 guidelines.
Electrical Knockout & Hole Saw Calculator
Convert nominal electrical conduit Trade Sizes (1/2 to 4-inch) into the exact physical fractional hole saw or hydraulic punch dimensions required for panel entry.
LED Strip Voltage Drop Calculator
Calculate DC voltage drop for 12V and 24V LED strip lighting. Determine if power injection or thicker AWG wire is required to prevent dimming and color shift.
Lighting & Foot-Candle Sizing Calculator
Calculate the total required fixture array and bare lumens needed to achieve a target foot-candle illumination density for any commercial or residential space.
Lighting Uniformity Ratio Calculator
Calculate critical commercial Avg/Min and Max/Min illuminance uniformity ratios for safety code compliance.
Lumen Depreciation Factor (LLMF) Calculator
Calculate specific LED baseline light-loss maintenance factors across targeted time durations using natural exponential decay formulas.
Electric Motor FLA & Branch Circuit Breaker Calculator
Estimate standard Full Load Amps (FLA) for single and 3-phase AC motors. Calculate Minimum Circuit Ampacity (MCA per NEC 430.22) and inverse-time breaker sizes per NEC Table 430.52.
Motor Run & Start Capacitor Sizing Calculator
Estimate full-load amps (FLA) and calculate the required Run and Start capacitor microfarad (µF) ratings for single-phase motors.
Electric Motor Locked Rotor Amps (LRA) Calculator
Analyze magnetic locked-rotor inrush limits, verify NEMA Code Letter variables, and size large industrial motors safely without tripping breakers.
Motor Overload (Heater) Sizing Calculator (NEC)
Determine exact National Electrical Code (NEC) maximum permitted thermal overload trip limits using FLA, Service Factor, and Temperature Rise data.
Motor Slip
Calculate AC induction motor synchronous speed, rotor slip RPM, and slip percentage per NEMA MG-1 and NEC guidelines.
Motor Startup Voltage Drop Calculator
Estimate conductor voltage drop at the motor terminals while a motor draws locked-rotor current (LRA) at start, using a resistance-only model for single-phase or three-phase copper feeders.
NEC Whole-House Load Estimator
Estimate your residential main service ampacity requirements according to NEC Article 220 standard calculations and demand factors.
NEMA Motor Starter Sizing Calculator
Determine the required NEMA size (00 to 9) for magnetic motor starters and contactors based on horsepower, phase, and system voltage according to NEMA ICS 2 standards.
Neutral Sizing
Size the neutral conductor for single-phase and three-phase services per NEC 220.61.
Ohm's Law Calculator
Instantly calculate Voltage, Current (Amps), Resistance (Ohms), or Power (Watts) by entering any two known circuit parameters.
Power Over Ethernet (PoE) Voltage Drop Calculator
Determine DC voltage loss, heat dissipation, and true delivered voltage on Cat5e/Cat6 runs powering Access Points and PTZ cameras over long distances.
Point to Point Fault Current
Calculate the degradation of available short circuit fault current over a conductor run to properly size downstream breaker AIC ratings.
Power Factor Correction Kvar
Calculate the exact reactive power (kVAR) required to correct an industrial electrical system's power factor and avoid utility penalty fees.
Power Factor Correction
Size capacitor banks by calculating exactly how much Reactive Power (kVAR) is required to correct system power factor and eliminate utility penalties.
Pull Box Sizing
Calculate NEC 314.28 minimum pull box dimensions for straight pulls, angle pulls, and U-pulls based on electrical conduit trade sizes.
Pv Combiner Fuse Sizing
Size solar array string fuses using the NEC 690.8 1.56× continuous irradiance multiplier. Ensure backfeed protection for parallel PV strings.
Pv String Sizing
Calculate the maximum number of solar panels that can be safely wired in series based on deep-freeze open-circuit voltage spikes and inverter DC limits.
Short Circuit Current Rating Sccr
Determine available transformer secondary fault current and establish the required Industrial Control Panel assembly Short-Circuit Current Rating (SCCR) per UL 508A Supplement SB and NEC 409.22.
Three Phase Voltage Drop
Calculate three-phase voltage drop in conductors from load, distance, and conductor size.
Transformer Full Load Amps (FLA) Calculator
Calculate rated primary and secondary full-load current for single-phase and three-phase transformers from kVA and winding voltages, with 125% and 250% multiples for reference against NEC Table 450.3(B).
Transformer Inrush Current Sizing Calculator
Determine primary Full Load Amps (FLA) and estimate peak transient magnetizing inrush current surges using empirical core multipliers.
Transformer kVA Size Calculator | 1-Phase & 3-Phase
Size single-phase and three-phase electrical transformers. Input your load amperage and voltage to determine base kVA, then apply the NEC 125% continuous load rule to find the correct standard commercial transformer size.
Transformer OCPD Sizing Calculator (NEC 450.3)
Determine primary and secondary overcurrent protection device (OCPD) sizes for transformers per NEC Table 450.3(B) reference limits.
Transformer Short Circuit Current Calculator (Infinite Bus)
Estimate the infinite-bus short-circuit current at a transformer secondary from kVA, secondary voltage and nameplate impedance, with secondary full-load current and the 100 / %Z multiplier shown.
Transformer Tap Rules Calculator (NEC 240.21)
Calculate drop conductor wire sizing under the NEC 240.21(B) 10-Foot and 25-Foot breaker tap rules. Calculates 10% and 33.3% minimum ampacity thresholds instantly.
NEC 300.5 Trench Depth Calculator
Determine mandatory OSHA and NEC excavation targets for direct burial, PVC raceways, and rigid metal conduits across all environmental locations.
OSHA Trench Shoring & Sloping Calculator
Determine safe visual sloping widths and massive excavation dirt volumes required to secure OSHA compliance in Type A, B, and C hazard soils.
Ups Sizing
Size a UPS from connected load, runtime requirement, and battery efficiency inputs.
Electrical Voltage Drop Calculator (VD)
Calculate NEC compliance for voltage drop across long wire runs. Compute copper/aluminum resistance limits for single-phase and three-phase circuits.
Wire Pull Tension and Sidewall Pressure Estimator
Estimate cable pulling tension and sidewall bearing pressure with a custom friction coefficient, cable weight, run length and number of 90-degree bends, using a conservative simplified capstan model.
NEC Wire Size (AWG) Ampacity Selector
Select code-compliant American Wire Gauge (AWG) based on amperage draw, temperature rating, and material, fully compliant with NEC Table 310.16 standards.