{
  "slug": "pa-power-sizing",
  "title": "PA Power/Wattage Sizing Calculator",
  "heading": "PA System Power Sizing Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/pa-power-sizing",
  "summary": "Estimate total wattage needed for room size and headroom.",
  "description": "Undersizing a PA leads to clipped, distorted sound at the volume a room actually needs, while oversizing wastes money on speakers you'll never push. A rough rule of thumb used by sound techs is roughly 10 watts of amplifier power per person for speech-level background music, 15-20 watts per person for live bands at moderate volume, and 20-30+ for loud rock/EDM shows, then adding 3-6 dB of headroom (which requires roughly 2-4x the continuous power rating) so peaks don't clip.",
  "formula": "Base watts = attendees × watts-per-person factor; total with headroom = base watts × headroom multiplier.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=pa-power-sizing",
  "inputs": [
    {
      "id": "attendees",
      "label": "Expected attendees",
      "kind": "number",
      "hint": null,
      "default": 200,
      "unit": null,
      "min": 1,
      "max": null
    },
    {
      "id": "genre",
      "label": "Show type",
      "kind": "select",
      "hint": null,
      "default": "band-moderate",
      "options": [
        {
          "value": "background",
          "label": "Background music / speech (~10 W/person)"
        },
        {
          "value": "band-moderate",
          "label": "Live band, moderate volume (~17 W/person)"
        },
        {
          "value": "loud-rock",
          "label": "Loud rock / EDM (~25 W/person)"
        }
      ]
    },
    {
      "id": "headroom",
      "label": "Headroom multiplier for peaks",
      "kind": "number",
      "hint": null,
      "default": 3,
      "unit": null,
      "min": 1,
      "max": 6
    }
  ],
  "outputs": [
    {
      "id": "total",
      "label": "Total peak system wattage needed",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "suggestedContinuous",
      "label": "Continuous (RMS) power target",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "perPerson",
      "label": "Watts per person used",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Expected attendees: 200",
      "Show type: Live band, moderate volume (~17 W/person)",
      "Headroom multiplier for peaks: 3"
    ],
    "outputs": [
      "Total peak system wattage needed: 10,200",
      "Continuous (RMS) power target: 3,400",
      "Watts per person used: 17"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter expected attendees.",
      "Enter show type.",
      "Enter headroom multiplier for peaks.",
      "Read your total peak system wattage needed on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "attendees": 120,
        "genre": "band-moderate",
        "headroom": 1.7999999999999998
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "attendees": 200,
        "genre": "band-moderate",
        "headroom": 3
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "attendees": 320,
        "genre": "band-moderate",
        "headroom": 4.800000000000001
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "Why does peak power need to be 2-4x continuous power?",
      "a": "Music has a high crest factor — brief transient peaks (kick drum hits, snare cracks) run well above the average continuous level, and an amplifier that only just covers the average will clip hard on every transient. Headroom of 3-6 dB (roughly 2-4x power) keeps those peaks clean."
    },
    {
      "q": "Does room type change this estimate?",
      "a": "Yes significantly — outdoor shows lose bass energy and overall level to open air and need more power than this indoor-oriented rule of thumb suggests, while small, reflective rooms need less because walls reinforce the sound. Treat this as a starting point, not a final spec, especially outdoors."
    },
    {
      "q": "Is more wattage always louder?",
      "a": "No — speaker sensitivity (dB SPL at 1W/1m) affects loudness as much as amplifier wattage, and every doubling of power only adds about 3 dB of perceived loudness. A high-sensitivity speaker at 500W can outperform a low-sensitivity speaker at 1000W."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/speaker-spl-distance",
    "https://www.revenuelab.fyi/toolbox/db-attenuation"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — PA Power/Wattage Sizing Calculator (https://www.revenuelab.fyi/toolbox/pa-power-sizing)"
}