Backup & Emergency Power Calculators
Calculate UPS capacity, generator fuel use, and battery backup runtime for sump pumps, medical devices, and home systems before the next outage hits.
New here? The guides answer the questions behind these calculators with worked numbers first, then link the right tool.
Deciding what to buy before you size it? Compare Powerwall vs generator · pure vs modified sine inverters — each states where each option wins, then links the sizing calculator.
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HAM Radio Emergency Power Calculator
Calculate backup power requirements for HAM radio equipment, considering transmit duty cycles, temperature impacts, and equipment power needs.
Sump Pump Battery Backup
Size the right battery for your sump pump before the next storm. Compare 12V and 24V systems and lead-acid vs lithium by runtime and duty cycle.
Backup Generator Fuel Usage
Backup generator calculator: estimate diesel or biodiesel fuel use and cost for a standby generator over your outage runtime, by size, load, and conditions.
Tesla Powerwall Sizing
Calculate the optimal Tesla Powerwall configuration based on home usage, solar production, and backup needs.
Medical Device Backup Power
Calculate reliable backup power requirements for critical medical equipment.
Personal Computing UPS Requirements
Calculate UPS sizing for gaming PCs, workstations, and home offices, accounting for peak power draws and desired runtime.
Basement Pump Power Needs
Calculate battery backup power for primary and secondary sump pumps to prevent basement flooding during power outages.
Fish Tank Power Backup
Calculate backup power needs for aquarium systems during outages to protect fish, maintain water temperature, and keep filtration systems running reliably.
Reptile Habitat Power Needs
Size backup power for reptile terrariums to maintain UV lighting, heat lamps, and temperature control during power failures.
Sewage Pump Power Needs
Size backup power systems for sewage pumps and ventilation to prevent basement bathroom backups during electrical outages.
Planner
Planning a whole-home backup system?
The whole-home backup planner chains this category's calculators into the order a real project runs in — load inventory, whole-home sizing, battery sizing, then solar — carrying each step's numbers into the next.
Open the planner