Free Online Calculators for Power, Energy & Electrical

Fast, accurate calculators for electrical engineers, homeowners, and DIYers. No sign-up. No ads in your way. Just results.

Electrical Calculators

⚡ kW to Amps Single & three phase conversion 🔌 Amps to kW Single & three phase conversion 📉 Voltage Drop Copper & aluminum wire 🔧 Wire Size AWG wire sizing by load & run 🛡️ Breaker Size What size breaker do you need?

Energy Calculators

💡 Electricity Cost Daily & monthly cost from watts 🏭 Generator Size Home & appliance sizing ☀️ Solar Panel Size Required panel wattage by usage

Battery & Backup Calculators

🔋 Battery Runtime 12V, 24V, 48V runtime from Ah & watts 🖥️ UPS Runtime Battery backup time estimate