DIY

What Size Generator Do You Need?

Built by Kevin Glover · @gloverbuilds · Verified formula

Calculate the wattage needed for backup power during outages. Home essentials, whole-house, or jobsite.

📅 Updated April 2026 ✅ Formula verified 📖 4 min read 🆓 Free · No sign-up

In this article

Sizing Your Generator
Portable vs Standby

Dimensionamento

Some watts de funcionamento + maior pico de partida. Geladeira: 700W (partida 2.200W). Bomba d'água: 1.000W (partida 3.000W). Iluminação: 300-600W. Total essencial típico: 3.500-5.000W. Um gerador de 5.000-7.500W cobre necessidades básicas. No Brasil, geradores são essenciais em áreas rurais e regiões com apagões frequentes.

Tipos

Inverter portátil (2.000-4.000W): silencioso, R$3.000-8.000. Convencional (3.500-10.000W): mais barulhento, R$2.000-6.000. Estacionário (7.500-22.000W): partida automática, R$15.000-50.000.

⚡ CalcWolf Insight

A whole-house standby generator (Generac, Kohler) installed with an automatic transfer switch is one of the highest-ROI home improvements in areas with frequent outages. It adds $3,000-5,000 to home value and is increasingly expected by buyers in storm-prone and rural areas.

Frequently asked questions

Qual potência para o essencial?▾

3.500-5.000W para geladeira + bomba + luzes. Para AC: 7.500W+.

Portátil ou estacionário?▾

Apagões ocasionais: portátil. Frequentes ou necessidades médicas: estacionário com partida automática.

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Kevin Glover · @gloverbuilds

Founder, CalcWolf · GLVTS · Blickr

All formulas sourced from primary references — IRS publications, peer-reviewed research, and official standards. Results are tested against independent reference calculators before publishing. Rates and brackets updated when official sources change. Editorial policy →