Describe the Problem
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Recent Calculations
Common Solve Paths
Ohm's Law
Solve voltage, current, resistance, or power.
Math Solver
Use scientific functions, trig, derivatives, and integrals.
Scientific Calculator
Use the keypad-style math calculator.
Graphing Calculator
Plot functions and find intersections.
Quadratic Solver
Solve ax² + bx + c = 0.
Derivative Calculator
Estimate slope at a point.
Integral Calculator
Estimate a definite integral numerically.
Three-Phase Power
Calculate kW and kVA for balanced loads.
Bulk Power MVA
Convert between line current and apparent power.
Power Triangle
Solve MW, MVAR, MVA, and power factor.
Per-Unit Base
Move impedance between study bases.
Grade Planner
See current grade and target average.
Formula Reference
Three-phase power
kW = √3 × V × A × PF ÷ 1000
Bulk MVA
MVA = √3 × kV × A ÷ 1000
Fault MVA
Fault MVA = √3 × kV × kA
Per unit base
Zpu,new = Zpu,old × (MVAnew / MVAold) × (kVold / kVnew)2