Free tools

UPS engineering calculators

Free, anonymous, mobile-friendly calculators for UPS dealers and system integrators worldwide. Backed by IEC 60364, IEEE 1188, and major OEM datasheets.

Battery Replacement Date Estimator

Predict when a UPS battery will need replacement based on temperature, chemistry, and duty cycle.

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UPS Battery Runtime Calculator

Calculate runtime in minutes from load, battery capacity, voltage, and chemistry. WPC and Peukert methods.

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UPS Sizing Calculator

Convert your equipment load list to the right UPS kVA rating with growth allowance and motor inrush.

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Cost of Downtime Calculator

Estimate the real cost of an outage — productivity, revenue, recovery — with Ponemon / ITIC / Uptime benchmarks.

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Generator + UPS Compatibility Checker

Right-size a backup generator for your UPS, accounting for rectifier topology, step load, and site derating.

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UPS PM Frequency Recommender

Generate an IEEE / NFPA 70B-aligned preventive-maintenance schedule by site criticality, battery chemistry, and age.

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Cable Sizing Calculator

IEC 60364-5-52 cable sizing with ampacity + voltage-drop dual constraint and regional ambient defaults.

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UPS TCO Calculator

5-yr total cost of ownership: CapEx + power loss + maintenance + battery refresh, discounted to NPV.

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UPS Room HVAC + Ventilation Sizing

Cooling capacity for UPS + battery heat load, plus IEC 62485 hydrogen-venting check for lead-acid.

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Generator Fuel Autonomy

Diesel BSFC curve + altitude / temperature derating + NFPA 110 24-hour rule check for life-safety installs.

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Harmonic Distortion / IEEE 519 Quick Check

Verify a UPS install against IEEE 519-2022 current distortion limits at the PCC.

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Three-Phase Imbalance

Voltage / current imbalance check vs ANSI / IEC thresholds, plus NEMA MG-1 motor derating factor.

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Battery Shipping Classification

UN number, IATA Section, packing instruction, and documentation list for shipping UPS replacement batteries.

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All thirteen Power Stack engineering calculators are now live. Tell us what to build next at george@power-stack.io.