Three-Phase Power Calculator

Three-Phase vs Single-Phase Power

Three-phase power is the standard for industrial and commercial electrical distribution because it delivers more power more efficiently than single-phase. Three conductors carry alternating currents 120° apart in phase, meaning power delivery is continuous and smoother — there's always a phase near its peak.

Efficiency advantage: Three-phase systems carry about 73% more power than a single-phase system using the same conductor size. Motors on three-phase power are simpler, more efficient, and self-starting. Large HVAC, pumps, compressors, and industrial equipment almost always use three-phase.

√3 (1.732) factor: The factor √3 appears because the three phases are geometrically offset by 120°. Line-to-line voltage is √3 times the phase voltage (e.g., 480V L-L = 277V L-N). Power calculations use line voltage and line current multiplied by √3 to account for all three phases.

Phase balance: In a balanced three-phase system, all three phases carry equal current and are exactly 120° apart. Unbalanced loads cause inefficiency, overheating, and motor damage. Always distribute single-phase loads evenly across all three phases.