Electrical & Power Calculators
Select an interactive calculator or sizing guide below to size battery backup banks, convert watts to amps across DC and AC circuits, or estimate required backup generator wattage.
Interactive Sizing & Conversion Calculators
Client-side engineering calculators with published formulas, worked examples, and NEC continuous-load references.
Generator Fuel Consumption Calculator
Estimate generator fuel use per hour, tank runtimes, and operating costs for gas, propane, and diesel models at 25%, 50%, 75%, and 100% load.
Generator Size Calculator
Calculate required generator wattage for home backup, RV camping, or jobsite tools with single-motor surge handling and 25% planning headroom.
UPS Battery Backup Run-Time Hours Calculator
Estimate how long an uninterruptible power supply or deep-cycle battery bank will power your equipment during an outage.
Battery Capacity & Sizing Calculator
Calculate battery energy storage in Watt-hours (Wh) and Amp-hours (Ah), evaluate usable capacity across chemistries, and size battery banks for loads.
Watts to Amps Electrical Calculator
Convert continuous power (Watts) to electrical current (Amps) across DC, single-phase AC, and balanced three-phase AC circuits.
Amps to Watts Electrical Calculator
Convert circuit current (Amps) and voltage (Volts) to real electrical power (Watts) and apparent power (VA) across DC and AC systems.
Solar Panel Tilt Angle Calculator
Calculate the optimal solar panel tilt angle and compass orientation for your latitude. Compare roof pitch angles, seasonal adjustments, and mounting options.
Solar Battery Calculator
Calculate the battery bank capacity needed for your off-grid or backup solar system. Size storage in kWh and Amp-hours based on daily usage and autonomy.
Solar Charge Controller Calculator
Calculate the charge controller size needed for your solar panels. Sizing calculator for MPPT and PWM controllers based on array wattage, battery voltage, and Voc.
Voltage Drop Calculator
Calculate voltage drop for DC, single-phase, and balanced three-phase circuits. Determine voltage loss, percentage drop, receiving voltage, and evaluate adjacent wire sizes.
Solar System Size Calculator
Calculate the solar system size in kW and approximate panel count required to power your home based on monthly kilowatt-hour consumption and local peak sun hours.
Three Phase Power Calculator
Calculate 3-phase real power (kW), apparent power (kVA), reactive power (kVAR), and line current (Amps). Supports line-to-line and line-to-neutral voltages with power factor.
Electricity Usage Calculator
Calculate daily and monthly electricity usage in Watt-hours (Wh) and kilowatt-hours (kWh) across household appliances with duty cycles and utility cost estimates.
Electricity Cost Calculator
Estimate monthly electric utility bills from kilowatt-hour (kWh) usage, base rates, fixed customer charges, riders, and taxes. Calculate true effective cost per kWh.
Inverter Size Calculator
Calculate continuous and peak surge inverter wattage, DC battery current draw, cable gauge (AWG), and fuse sizing across 12V, 24V, and 48V systems.
Engineering Sizing Guides & Outage Planning
Detailed residential power guides with appliance wattage benchmarks, worked calculations, and 1-click calculator presets.
What Size Generator Do I Need for My House?
Calculate required continuous running wattage and motor startup surge demand for your home during utility outages using our four-step sizing method and 5.1 kW worked storm scenario.
What Size Generator Do I Need to Run a Refrigerator?
Determine exact running and compressor starting wattage for modern Energy Star refrigerators, deep freezers, and simultaneous household outage loads.
What Does Ah Mean on a Battery? Amp-Hours Explained
Understand battery charge capacity, convert Amp-hours to Watt-hours (Wh), and evaluate how chemistry, depth of discharge, and Peukert losses determine real-world runtime.
What Is a Watt-Hour (Wh)? Watts vs. Watt-Hours Explained
Discover the difference between instantaneous power (Watts) and energy consumed over time (Watt-hours), with practical battery runtime and utility billing calculations.
How Long Will a 100Ah Battery Last? 12V Appliance Runtime Guide
Realistic delivered runtime estimates for refrigerators, CPAP machines, laptops, TVs, and inverters across LiFePO4 and lead-acid deep-cycle batteries.
Solar Panels in Series vs Parallel: Wiring Diagrams & Sizing
Compare solar panels in series vs parallel. See clear wiring diagrams, calculate array voltage and current, and size charge controllers for off-grid and RV systems.
How Much Energy Does a Solar Panel Produce?
Learn daily, monthly, and annual solar panel electricity generation. 400W reference examples, peak sun hours, system deratings, and production variables.
How Long Does It Take to Charge a Battery With Solar Panels?
Calculate solar battery charging hours and calendar days using battery capacity, peak sun hours, MPPT vs PWM efficiency, and chemistry absorption stages.
How Many Amp Hours Do I Need for a Battery Bank?
Calculate total battery bank amp-hours from daily appliance Watt-hours, nominal voltage (12V, 24V, 48V), autonomy days, usable depth of discharge, and inverter efficiency.
How Many Watts on a 15-Amp or 20-Amp Circuit?
Determine real-world wattage capacity for 120V household branch circuits. Compare nominal limits against the NEC 80% continuous safety rule and review 14 AWG vs 12 AWG wire requirements.