Use this JavaScript-based UPS load calculator to estimate recommended UPS capacity and approximate battery requirement from total load, backup time, and power factor. This is a quick planning tool for initial sizing and product comparison.
Calculator Inputs
Total load in watts
Backup time in hours
Power factor
Built-in planning margin for sizing
Enter Load Details
Provide the total connected load, required backup time, power factor, battery bank voltage, and battery assumptions. The calculator applies a 20% sizing margin and uses the selected battery efficiency for practical estimation.
Typical range: 0.7 to 0.9 depending on load type.
Common values: 12V, 24V, 48V, 96V, 120V, 192V.
Typical planning value: 80% to 90%.
Optional note to help describe the selected battery option.
Enter the Ah rating of one battery unit, typically a 12V battery.
Results will appear here after calculation. Actual battery bank voltage and UPS model selection depend on product design and application requirement.
How the Calculator Works
Recommended UPS capacity is calculated from `load / power factor` and then increased by a 20% planning margin.
Battery requirement is estimated from `load x backup time / selected battery efficiency`.
Approximate battery Ah is shown against the selected battery bank voltage for quick planning.
Approximate battery count is shown as the number of 12V battery units required to build the selected battery bank voltage.
If a single battery Ah value is entered, the calculator estimates batteries in series, strings in parallel, and approximate total battery count.
A suggested standard UPS rating is selected from common commercial sizes for easier product mapping.
This tool is useful for early-stage selection. Final UPS sizing should still consider starting current, battery type, DC bus voltage, inverter efficiency, redundancy requirement, and future load expansion.
