Generator Wattage Calculator
Estimate running watts, starting surge, and a practical generator size for selected backup loads.
Open calculatorBackup Power Calculators
Home Power & Project Calculators
Free calculators for backup power, generators, portable power stations, solar charging, RV camping power, and home outage planning.
Popular calculators
- Generator Wattage Calculator
Estimate running watts, starting surge, and a practical generator size for selected backup loads.
- Portable Power Station Runtime Calculator
Estimate how long a portable power station can run a load after efficiency losses and reserve.
- Refrigerator Backup Time Calculator
Estimate refrigerator or freezer backup time using battery capacity, duty cycle, and inverter efficiency.
- Solar Panel Charging Time Calculator
Estimate solar charging time from battery size, charge target, panel watts, sun hours, and system efficiency.
- UPS Runtime Calculator
Estimate UPS runtime for routers, computers, NAS devices, and other small electronics.
Calculator category
Backup Power Calculators
Estimate power needs for outages, generators, battery stations, solar charging, UPS devices, CPAP backup, and RV or camping loads.
View categoryWhy use these calculators
- They use neutral formulas for planning estimates.
- Inputs and assumptions are visible instead of hidden.
- Results are estimates only and should be checked against device labels, manuals, and qualified guidance.
Safety note
These tools do not provide wiring instructions, medical advice, food safety guarantees, or emergency instructions. For safety-critical backup plans, consult qualified professionals and the equipment manufacturer.
Backup power tools
Start with a focused calculator, then compare related tools for a broader outage or camping plan.
Portable Power Station Runtime Calculator
Estimate how long a portable power station can run a load after efficiency losses and reserve.
Open calculatorRefrigerator Backup Time Calculator
Estimate refrigerator or freezer backup time using battery capacity, duty cycle, and inverter efficiency.
Open calculatorSolar Panel Charging Time Calculator
Estimate solar charging time from battery size, charge target, panel watts, sun hours, and system efficiency.
Open calculatorUPS Runtime Calculator
Estimate UPS runtime for routers, computers, NAS devices, and other small electronics.
Open calculatorCPAP Battery Backup Calculator
Estimate CPAP backup runtime and nights from battery capacity, humidifier use, reserve, and efficiency.
Open calculatorRV / Camping Power Calculator
Estimate daily campsite energy use, trip battery needs, and optional solar recharge.
Open calculatorHome Outage Backup Planner
Plan 24, 48, or 72 hour backup needs for critical home loads using battery and generator estimates.
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