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Event Power Calculator — Generator Sizing by Equipment Load

Size your generator and plan circuits by adding your event equipment load list

Generator Size

5 kW

Load

3,250 W

With Margin

4,063 W

Circuits

3

Recommended Generator

5 kW

4,063 W with 25% margin

Base Load

3,250 W

Amps (120V)

34

Circuits

3

Power Breakdown

Sound System (PA) ×12,000 W
String Lights (100 ft LED) ×4200 W
Food Warmer / Chafing Dish ×31,050 W

What You'll Need

HUANCHAIN 50 FT 12/3 Gauge Heavy Duty Outdoor Extension Cord Waterproof with Lighted end, Flexible Cold-Resistant 3 Prong Electric Cord Outside, 15Amp 1875W 12AWG SJTW, Yellow, ETL

HUANCHAIN 50 FT 12/3 Gauge Heavy Duty Outdoor Extension Cord Waterproof with Lighted end, Flexible Cold-Resistant 3 Prong Electric Cord Outside, 15Amp 1875W 12AWG SJTW, Yellow, ETL

$41.994.8
View on Amazon
Surge Protector Power Strip - HANYCONY 8 Outlets 4 USB (2 USB C) Charging Ports, Multi Plug Outlet Extender, 5Ft Braided Extension Cord, Flat Plug Wall Mount Desk Charging Station for Home Office ETL

Surge Protector Power Strip - HANYCONY 8 Outlets 4 USB (2 USB C) Charging Ports, Multi Plug Outlet Extender, 5Ft Braided Extension Cord, Flat Plug Wall Mount Desk Charging Station for Home Office ETL

$9.994.8
View on Amazon
Jackery Explorer 500 v2 Portable Power Station, 512Wh LiFePO4 Battery, 500W AC/1000W Peak, Solar Generator for Camping, Outdoors, and Power Outages

Jackery Explorer 500 v2 Portable Power Station, 512Wh LiFePO4 Battery, 500W AC/1000W Peak, Solar Generator for Camping, Outdoors, and Power Outages

$339.004.5
View on Amazon
Disposable Chafing Dish Buffet Set - Set of 6 / 36pc - Half-Sized Catering Chafers and Buffet Warmers, Buffet Server, Food Warmers for Parties, Catering Supplies for Party - Includes Fuel Cans

Disposable Chafing Dish Buffet Set - Set of 6 / 36pc - Half-Sized Catering Chafers and Buffet Warmers, Buffet Server, Food Warmers for Parties, Catering Supplies for Party - Includes Fuel Cans

$39.994.6
View on Amazon
Dixie Ultra, Large Paper Plates, 10 Inch, 172 Count (4 packs of 43 plates), 3X Stronger*, Heavy Duty, Microwave-Safe, Soak-Proof, Cut Resistant, Disposable Plates For Heavy, Messy Meals

Dixie Ultra, Large Paper Plates, 10 Inch, 172 Count (4 packs of 43 plates), 3X Stronger*, Heavy Duty, Microwave-Safe, Soak-Proof, Cut Resistant, Disposable Plates For Heavy, Messy Meals

$22.474.5
View on Amazon
Jofefe 20pcs Mini Place Card Holders, Cute Table Number Holders, Small Size Table Card Holder Tables Number Stands, Wire Photo Picture Menu Clips for Wedding centerpieces, Anniversary Party (Gold)

Jofefe 20pcs Mini Place Card Holders, Cute Table Number Holders, Small Size Table Card Holder Tables Number Stands, Wire Photo Picture Menu Clips for Wedding centerpieces, Anniversary Party (Gold)

$6.994.6
View on Amazon
HUANCHAIN 50 FT 12/3 Gauge Heavy Duty Outdoor Extension Cord Waterproof with Lighted end, Flexible Cold-Resistant 3 Prong Electric Cord Outside, 15Amp 1875W 12AWG SJTW, Yellow, ETL

HUANCHAIN 50 FT 12/3 Gauge Heavy Duty Outdoor Extension Cord Waterproof with Lighted end, Flexible Cold-Resistant 3 Prong Electric Cord Outside, 15Amp 1875W 12AWG SJTW, Yellow, ETL

$41.994.8
View on Amazon
Surge Protector Power Strip - HANYCONY 8 Outlets 4 USB (2 USB C) Charging Ports, Multi Plug Outlet Extender, 5Ft Braided Extension Cord, Flat Plug Wall Mount Desk Charging Station for Home Office ETL

Surge Protector Power Strip - HANYCONY 8 Outlets 4 USB (2 USB C) Charging Ports, Multi Plug Outlet Extender, 5Ft Braided Extension Cord, Flat Plug Wall Mount Desk Charging Station for Home Office ETL

$9.994.8
View on Amazon
Jackery Explorer 500 v2 Portable Power Station, 512Wh LiFePO4 Battery, 500W AC/1000W Peak, Solar Generator for Camping, Outdoors, and Power Outages

Jackery Explorer 500 v2 Portable Power Station, 512Wh LiFePO4 Battery, 500W AC/1000W Peak, Solar Generator for Camping, Outdoors, and Power Outages

$339.004.5
View on Amazon
Disposable Chafing Dish Buffet Set - Set of 6 / 36pc - Half-Sized Catering Chafers and Buffet Warmers, Buffet Server, Food Warmers for Parties, Catering Supplies for Party - Includes Fuel Cans

Disposable Chafing Dish Buffet Set - Set of 6 / 36pc - Half-Sized Catering Chafers and Buffet Warmers, Buffet Server, Food Warmers for Parties, Catering Supplies for Party - Includes Fuel Cans

$39.994.6
View on Amazon
Dixie Ultra, Large Paper Plates, 10 Inch, 172 Count (4 packs of 43 plates), 3X Stronger*, Heavy Duty, Microwave-Safe, Soak-Proof, Cut Resistant, Disposable Plates For Heavy, Messy Meals

Dixie Ultra, Large Paper Plates, 10 Inch, 172 Count (4 packs of 43 plates), 3X Stronger*, Heavy Duty, Microwave-Safe, Soak-Proof, Cut Resistant, Disposable Plates For Heavy, Messy Meals

$22.474.5
View on Amazon
Jofefe 20pcs Mini Place Card Holders, Cute Table Number Holders, Small Size Table Card Holder Tables Number Stands, Wire Photo Picture Menu Clips for Wedding centerpieces, Anniversary Party (Gold)

Jofefe 20pcs Mini Place Card Holders, Cute Table Number Holders, Small Size Table Card Holder Tables Number Stands, Wire Photo Picture Menu Clips for Wedding centerpieces, Anniversary Party (Gold)

$6.994.6
View on Amazon

As an Amazon Associate, we earn from qualifying purchases.

Example Calculations

1Outdoor Wedding — PA + Lights + Food

Inputs

PA System1 × 2,000W
String Lights4 × 50W
Food Warmers3 × 350W
Safety Margin25%

Result

Generator5 kW
Base Load3,250 W
With Margin4,063 W
Circuits3

2,000 + 200 + 1,050 = 3,250W. With 25% margin: 4,063W. 4,063 / 800 = 5.1 kVA → 5 kW. Amps: 4,063 / 120 = 34A → 3 circuits.

2Festival Stage — Full Production

Inputs

PA System1 × 2,000W
Stage Lights6 × 500W
Portable AC1 × 3,500W
Safety Margin25%

Result

Generator10 kW
Base Load8,500 W
With Margin10,625 W
Circuits6

2,000 + 3,000 + 3,500 = 8,500W. With 25%: 10,625W. 10,625 / 800 = 13.3 kVA → 15 kW. Amps: 89A → 6 circuits.

Frequently Asked Questions

Q

What size generator do I need for an outdoor event?

A typical outdoor wedding or party needs 5–10 kW. A PA system (2,000W) plus 400 ft of string lights (200W) plus 3 food warmers (1,050W) totals 3,250W base load. With a 25% safety margin, you need a 5 kW generator. Add portable AC or heaters and you jump to 7.5–10 kW.

  • Small event (PA + lights): 3–5 kW generator
  • Medium event (+ food service): 5–7.5 kW
  • Large event (+ HVAC): 10–15 kW
  • Always add 25% safety margin for startup surges
  • Quiet inverter generators preferred for events
EquipmentWattsGenerator
PA + String Lights2,200W3 kW
+ Food Warmers3,250W5 kW
+ Portable AC6,750W10 kW
Full Production10,000W+15 kW
Q

How many circuits do I need for event equipment?

Divide total wattage by 120V, then divide amps by 15 for standard circuits. A 3,250W setup draws 27 amps, requiring 2 circuits. Never load a circuit above 80% (12A per 15A circuit). Run audio and lighting on separate circuits to prevent flicker and hum.

  • Formula: Circuits = Total Watts / 120V / 15A
  • 80% rule: max 12A per 15A circuit
  • Audio and lighting on separate circuits
  • 3,250W = 27A = 2 circuits minimum
  • Coffee urns and heaters on dedicated circuits
Q

How much power does a PA system use?

A typical event PA system draws 1,500–2,500 watts. A simple 2-speaker setup for 100 guests uses about 1,500W. A DJ setup with subwoofer, mixer, and laptop draws 1,500–2,000W. Live bands with amplifiers and monitors can require 3,000–5,000W depending on size.

  • 2-speaker PA for speeches: 1,500W
  • DJ setup (speakers + sub + mixer): 2,000W
  • Live band (small): 3,000W
  • Live band (large): 5,000W+
  • Always run audio on a dedicated circuit
Q

Do LED string lights use a lot of power?

LED string lights use about 0.5 watts per foot. 100 feet of LED bistro lights draws only 50 watts. Even 400 feet (a large venue) uses just 200 watts — less than a single food warmer. Traditional incandescent strings use 5–10x more power, so always choose LED for events.

  • LED string lights: ~0.5W per foot
  • 100 ft of LED: 50 watts
  • 400 ft of LED: 200 watts
  • Incandescent: 5–10W per foot (avoid)
  • LED strings can share circuits with other low-draw items

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Last Updated: Jun 18, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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