{
    "name": "Three-Phase Power Calculator",
    "url": "https://calculators.geekmidst.com/calculators/three-phase-power-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/three-phase-power-calculator.md",
    "category": "Energy & environment",
    "description": "Convert between three-phase current and power: kW, kVA and kVAR from line voltage, current and power factor, or the current a given kW load draws.",
    "summary": "In a balanced three-phase system, real power is √3 × line voltage × line current × power factor. Use it either way: amps to kW, or kW to amps.",
    "also_called": [
        "3-phase power calculator",
        "kW to amps calculator (three-phase)",
        "Three-phase current calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "mode",
            "label": "Find",
            "type": "segmented",
            "default": "from_current",
            "options": {
                "from_current": "Power from current",
                "from_power": "Current from power"
            }
        },
        {
            "name": "voltage",
            "label": "Line-to-line voltage",
            "type": "number",
            "default": "400",
            "unit": "V"
        },
        {
            "name": "current",
            "label": "Line current",
            "type": "number",
            "default": "10",
            "unit": "A",
            "shown_when": {
                "mode": "from_current"
            }
        },
        {
            "name": "power_kw",
            "label": "Real power",
            "type": "number",
            "default": "11",
            "unit": "kW",
            "shown_when": {
                "mode": "from_power"
            }
        },
        {
            "name": "pf",
            "label": "Power factor",
            "type": "number",
            "default": "0.85"
        }
    ],
    "outputs": [
        {
            "key": "result",
            "label": "Result",
            "format": "text"
        },
        {
            "key": "power_kw",
            "label": "Real power",
            "format": "number"
        },
        {
            "key": "current_a",
            "label": "Line current",
            "format": "number"
        },
        {
            "key": "kva",
            "label": "Apparent power",
            "format": "number"
        },
        {
            "key": "kvar",
            "label": "Reactive power",
            "format": "number"
        }
    ],
    "formula": {
        "text": "P = √3 × V_L × I_L × PF;  S = √3 × V_L × I_L;  Q = S × sin(arccos PF);  I_L = P ÷ (√3 × V_L × PF)",
        "variables": {
            "V_L": "line-to-line voltage",
            "I_L": "line current",
            "PF": "power factor",
            "S": "apparent power",
            "Q": "reactive power"
        }
    },
    "worked_example": {
        "inputs": {
            "mode": "from_current",
            "voltage": "400",
            "current": "10",
            "power_kw": "11",
            "pf": "0.85"
        },
        "steps": [
            "S = √3 × 400 × 10 = 6,928 VA = 6.928 kVA.",
            "P = 6.928 × 0.85 = 5.889 kW.",
            "Q = 6.928 × √(1 − 0.85²) = 6.928 × 0.5268 = 3.65 kVAR."
        ],
        "result": "A balanced 400 V three-phase load drawing 10 A at 0.85 power factor uses 5.889 kW."
    },
    "interpretation": "Use current-from-power to size cables and protective devices, then apply the derating and starting-current rules in your local wiring regulations.",
    "assumptions": [
        "The load is balanced across the three phases.",
        "Voltage is line-to-line (e.g. 400 V, not the 230 V phase-to-neutral value)."
    ],
    "limitations": [
        "Unbalanced loads need per-phase calculation.",
        "Motor starting currents are several times running current and are not included."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Where does √3 come from?",
            "answer": "In a three-phase system the line-to-line voltage is √3 times the phase voltage, so total power 3 × V_phase × I equals √3 × V_line × I."
        },
        {
            "question": "What if I only know phase-to-neutral voltage?",
            "answer": "Multiply it by √3 (about 1.732) to get line-to-line voltage; 230 V phase voltage gives about 400 V line voltage."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Power Factor Correction Calculator",
            "url": "https://calculators.geekmidst.com/calculators/power-factor-correction-calculator"
        },
        {
            "name": "Commercial Demand Charge Calculator",
            "url": "https://calculators.geekmidst.com/calculators/commercial-demand-charge-calculator"
        },
        {
            "name": "Solar Inverter Sizing Calculator",
            "url": "https://calculators.geekmidst.com/calculators/solar-inverter-sizing-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}