UPS & Backup Power
UPS Runtime Calculator
How long a UPS will run your load, from battery capacity, voltage and inverter efficiency.
runtime = Ah × V × DoD × efficiency ÷ load
Also called ups backup time · how long will ups last
Energy & Environment · 7 calculators
UPS & Backup Power Calculators
UPS runtime and size, inverter and battery bank sizing, backup energy and total load wattage.
UPS & Backup Power
UPS Size Calculator
UPS VA and watt rating for your equipment, with headroom and the battery needed for runtime.
VA = watts ÷ power factor
Also called va rating calculator · what size ups do i need
UPS & Backup Power
Battery Bank Calculator
Series and parallel layout to build a battery bank of a target voltage and capacity.
series = target V ÷ battery V
Also called battery bank design · series parallel battery
UPS & Backup Power
Inverter Size Calculator
Inverter rating for a solar array or off-grid load, including surge headroom.
inverter W = array Wp ÷ DC:AC ratio × (1 …
Also called what size inverter do i need · inverter sizing calculator
UPS & Backup Power
Battery Backup Calculator
Battery capacity needed to back up your home for a set number of hours.
kWh = load × hours ÷ efficiency ÷ depth o…
Also called home battery size · backup power calculator
UPS & Backup Power
Battery Capacity Calculator
Battery bank capacity in Ah and kWh for a required runtime, allowing for depth of discharge.
Ah = load W × hours ÷ efficiency ÷ DoD ÷ …
Also called battery bank size · ah calculator
UPS & Backup Power
Electrical Load Calculator
Total connected load, demand load and current draw for a panel or circuit.
Demand = connected load × demand factor +…
Also called panel load calculator · connected load
Key ups & backup power formulas
| UPS Runtime | runtime = Ah × V × DoD × efficiency ÷ load |
|---|---|
| UPS Size | VA = watts ÷ power factor · battery Ah = Wh ÷ voltage |
| Battery Bank | series = target V ÷ battery V · strings = target kWh ÷ string kWh |
| Inverter Size | inverter W = array Wp ÷ DC:AC ratio × (1 + headroom) |
| Battery Backup | kWh = load × hours ÷ efficiency ÷ depth of discharge |
| Battery Capacity | Ah = load W × hours ÷ efficiency ÷ DoD ÷ system V |
| Electrical Load | Demand = connected load × demand factor + 25% of the largest motor |