Free tools to help you size and plan a solar system, one at a time — starting with the panel calculator.
Jump to the tools for a specific part of your solar design.
Size a complete off-grid system, step by step.
Array size, tilt, efficiency, shading & layout.
Bank sizing, runtime, charging & autonomy.
Cable, fuses, voltage drop & string sizing.
ROI, bill savings, output & emissions.
Compare solar quotes fairly — total price ÷ watts gives cost per watt and per kW.
Open calculator → ConverterConvert energy (kWh) to average power (kW) over a time period — with the reverse kW to kWh too.
Open calculator → ConverterConvert apparent power (kVA) to real power (kW) using the power factor — kW = kVA × PF, with the reverse too.
Open calculator →Find out how many panels you need based on your monthly electricity usage and available sunlight.
Open calculator →Match the right inverter size to your appliances and total system load.
Open calculator →Compare Lithium and Lead-acid capacity requirements for backup hours.
Open calculator →Pick the right cable gauge for your system to avoid voltage drop and overheating.
Open calculator →Know your cable size? Find the actual voltage drop in volts and percent for a given length and current — and whether it's within safe limits.
Open calculator →Estimate your payback period and long-term savings from going solar.
Open calculator →See how much solar takes off your electricity bill each month, each year, and over 25 years — including rising prices and how much of your bill it covers.
Open calculator →Size the battery and solar array your home needs to ride out a power cut — pick your appliances, set backup hours, and get battery Ah, array watts and panel count.
Open calculator →Find out how many solar panels it takes to charge your electric car for free — daily km, consumption and sun hours in, array size and panel count out.
Open calculator →Find the right MPPT or PWM controller size for your array and battery bank.
Open calculator →Find the optimal panel tilt angle for your latitude — year-round, winter, or summer optimized.
Open calculator →Find the right backup generator size, including starting surge from motors and AC units.
Open calculator →Add every appliance to get your daily energy use, monthly usage, and peak simultaneous load.
Open calculator →Answer a few questions and get a full system recommendation: panels, battery, inverter, and controller.
Open calculator →Find the max and min panels per series string using temperature-corrected Voc and Vmp, matched to your inverter's voltage window.
Open calculator →Estimate how many kWh your system produces per day, month, and year from its size, local peak sun hours, and real-world losses.
Open calculator →See how much carbon dioxide your solar system avoids each year and over 25 years — plus the equivalent in trees planted and car kilometres.
Open calculator →See how your panels' output declines year by year, what they'll produce after 10, 20, and 25 years, and their total lifetime energy.
Open calculator →See how much power your panels lose on hot days from the temperature coefficient — and the real output you'll get at a given cell temperature.
Open calculator →Estimate how much energy your array loses to shade, see your effective output, and learn why series wiring makes partial shade so costly.
Open calculator →Enter your available roof area and panel details to see how many panels fit and the system size in kW you can install — sizing by space, not by bill.
Open calculator →Get your inverter loading ratio from array and inverter sizes, see if it's in the ideal range, and estimate the clipping loss from oversizing.
Open calculator →Enter panel specs and your wiring layout to get the array's voltage, current, power, and maximum open-circuit voltage — series adds volts, parallel adds amps.
Open calculator →Convert battery capacity between amp-hours and kilowatt-hours from the voltage, and see the usable energy at your depth of discharge.
Open calculator →Enter load, fuel rate, and price to see how much fuel your generator burns and what it costs per hour, day, and month — and where solar cuts the bill.
Open calculator →Enter a panel's rated watts and dimensions to get its efficiency percentage and power density in watts per square metre.
Open calculator →Size an off-grid battery bank for a set number of days without sun — from daily use, depth of discharge, and system voltage, in kWh and Ah.
Open calculator →Find the minimum spacing between tilted solar rows to avoid inter-row shading — from module length, tilt angle, and your latitude.
Open calculator →Convert power to current in one step — enter watts and voltage to get amps, using P = V × I. Essential for sizing fuses, breakers, and cables.
Open calculator →Get the correct overcurrent protection size for a solar circuit using the standard 1.25 safety factor and the next standard fuse rating.
Open calculator →Already have a battery? Find out how many hours it will last on a given load, after depth of discharge and inverter losses.
Open calculator →See how many hours it takes to charge your battery from its capacity and charging current, including the C-rate and a real-world efficiency allowance.
Open calculator →Find the safe charge or discharge current from your battery capacity and C-rate, using I = Ah × C — plus the nominal charge/discharge time.
Open calculator →Size a solar water pump from your flow rate and total head — get the hydraulic power, pump power, and the solar array size needed to run it.
Open calculator →Calculate total dynamic head for any well or irrigation pump — static lift, pipe friction and flow losses — then get the hydraulic power, pump size and solar array needed to run it.
Open calculator →Size the water tank your farm or homestead needs to store a full day of supply — daily consumption, pump flow and sun hours in, tank size and required pump run hours out.
Open calculator →