{
    "name": "Capacitor Energy Calculator",
    "url": "https://calculators.geekmidst.com/calculators/capacitor-energy-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/capacitor-energy-calculator.md",
    "category": "Science & engineering",
    "description": "Calculate the energy stored in a capacitor and its charge from capacitance in F, mF, µF, nF or pF and the voltage across it, using E = ½CV² and Q = CV.",
    "summary": "A charged capacitor stores energy E = ½CV². Because energy rises with the square of voltage, doubling the voltage stores four times as much.",
    "also_called": [
        "Capacitor charge calculator",
        "Stored energy 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": "capacitance",
            "label": "Capacitance",
            "type": "number",
            "default": "1000"
        },
        {
            "name": "cap_unit",
            "label": "Capacitance unit",
            "type": "select",
            "default": "uf",
            "options": {
                "f": "farads (F)",
                "mf": "millifarads (mF)",
                "uf": "microfarads (µF)",
                "nf": "nanofarads (nF)",
                "pf": "picofarads (pF)"
            }
        },
        {
            "name": "voltage",
            "label": "Voltage across the capacitor",
            "type": "number",
            "default": "50",
            "unit": "V"
        }
    ],
    "outputs": [
        {
            "key": "energy",
            "label": "Stored energy",
            "format": "text"
        },
        {
            "key": "energy_j",
            "label": "Stored energy",
            "format": "number"
        },
        {
            "key": "energy_wh",
            "label": "Stored energy",
            "format": "number"
        },
        {
            "key": "charge",
            "label": "Charge",
            "format": "text"
        },
        {
            "key": "charge_c",
            "label": "Charge",
            "format": "number"
        }
    ],
    "formula": {
        "text": "E = ½ × C × V²;  Q = C × V;  Wh = J ÷ 3600",
        "variables": {
            "C": "capacitance in farads",
            "V": "voltage in volts",
            "E": "energy in joules",
            "Q": "charge in coulombs"
        }
    },
    "worked_example": {
        "inputs": {
            "capacitance": "1000",
            "cap_unit": "uf",
            "voltage": "50"
        },
        "steps": [
            "C = 1000 µF = 0.001 F.",
            "E = ½ × 0.001 × 50² = 1.25 J.",
            "Q = 0.001 × 50 = 0.05 C = 50 mC."
        ],
        "result": "A 1000 µF capacitor charged to 50 V stores 1.25 J and holds 50 mC of charge."
    },
    "interpretation": "Only part of this energy is usable if the load stops working below some minimum voltage: usable energy = ½C(V₁² − V₂²).",
    "assumptions": [
        "Ideal capacitor with constant capacitance."
    ],
    "limitations": [
        "Leakage, ESR losses and capacitance tolerance (often ±20%) are not included."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Is a charged capacitor dangerous?",
            "answer": "Large capacitors at high voltage can deliver a dangerous shock long after power is removed. Discharge them through a suitable resistor before handling."
        },
        {
            "question": "Why only half of CV²?",
            "answer": "The voltage rises from 0 to V as charge is added, so the average voltage during charging is V ÷ 2."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Ohm’s Law Calculator",
            "url": "https://calculators.geekmidst.com/calculators/ohms-law-calculator"
        },
        {
            "name": "Electric Power Calculator",
            "url": "https://calculators.geekmidst.com/calculators/electric-power-calculator"
        },
        {
            "name": "AC Impedance Calculator",
            "url": "https://calculators.geekmidst.com/calculators/ac-impedance-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}