Some of the largest UPS systems in the world exceed 50 megawatts (MW), supporting industries that require constant, high-capacity energy. UPS systems come in a wide range of sizes, from compact models designed for home offices to industrial-grade solutions built for power-hungry. . This article explains how to determine the right uninterruptible power supply size to fit your needs. How Big Should My Uninterruptible Power Supply Be? The three significant factors to consider when setting up a UPS are the intended load (i. This calculator helps determine the correct UPS capacity in VA (Volt-Amps) and required battery runtime based on your connected load and desired backup duration. . When purchasing a single-phase lithium-ion UPS system, it's essential to match the system's size to your specific needs. What is an Uninterruptible Power Supply (UPS)? A UPS. . Correctly sizing the UPS is critical: under sizing the UPS can lead to dropping your load and oversizing can lead to lower efficiency, increased utility costs, wasted floor space, increased peripheral equipment cost, and more.