Technology & Systems Calculators

Utility calculators for sysadmins, DevOps, network engineers, and IT professionals. Calculate RAID storage and fault tolerance, UPS battery runtime, server rack space & power, CCTV video storage, subnet masks, and byte sizing.

UPS Battery Runtime

Estimate battery backup runtime for tech equipment based on continuous wattage, VA rating, and battery Ah.

UPS & Load Configuration

Total Power Load (Watts)

Watts

Continuous draw of all IT equipment plugged into the battery-backed outlets.

UPS Unit Capacity Presets

Total Battery Pack Voltage (V)

12V (single), 24V (2 in series), 48V (4 in series)

Battery Pack Capacity (Ah)

Amp-hours rating stamped on the internal lead-acid battery

Battery Health / Age

Inverter Efficiency (%)

Standard DC-to-AC conversion loss (80-90% typical)

Runtime Estimates

Estimated Backup Runtime

36 min

Supporting continuous 250W load until depletion

Battery Energy216 Wh184 Wh usable

Recommended UPS≥ 550 VA+25% safety headroom

Runtime Curve Benchmarks

At 50% Load (450W):21 minutes

At 100% Full Load (900W):9 minutes

UPS & Battery Sizing Guidelines

Peukert's Effect: Lead-Acid batteries do not discharge linearly. If you pull 80%+ of a UPS's capacity, high internal heat resistance reduces the actual energy output by up to 30%.

Graceful Shutdown: The primary purpose of a UPS in IT infrastructure is not to power hardware for hours, but to bridge brief power flickers and give tools like Network UPS Tools (NUT) or apcupsd time to shut servers down cleanly.