Calculators
Motor Efficiency Economic Calculator
IE2 vs. IE3/IE4 motor upgrade economics — energy savings, demand savings, simple payback, NPV, and lifetime CO2 avoided. Baseline efficiencies follow NEMA MG-1 Table 12-12 (4-pole, 1800 RPM); test method per IEEE Std 112 Method B; class definitions per IEC 60034-30-1.
Method: Shaft power Pshaft = HP · LF · 0.7457 (kW). Input electrical power Pelec = Pshaft / η. Energy delta ΔP = Pshaft · (1/ηbase − 1/ηup). Annual energy savings ΔE = ΔP · hours. Annual savings = ΔE · rate + ΔP · demand · 12. Simple payback = cost / annual savings. NPV = savings · [(1 − (1+r)−n) / r] − upgrade cost. CO2 avoided = ΔE · life · EF / 2205 (lb→tonne). Power factor effect ignored — PF improvement may unlock additional savings via utility penalty avoidance. References: IEEE Std 112-2017; NEMA MG-1 2021 Table 12-12; IEC 60034-30-1:2014; 10 CFR 431 Subpart B (EISA 2007); EPA eGRID2022.
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© 2026 Inflection Point Engineering, LLC. All rights reserved.