Another useful calculator: Circuit Breaker Size Calculator

08/14/2025

Free online tool Circuit Breaker Size Calculator

When is it useful?

• Designing home or office electrical panels
• Selecting breakers for specific equipment (e.g., soldering stations, UPS, compressors)
• Replacing an old breaker and ensuring proper protection and performance

Example: How to Calculate Breaker Size for a Refrigerator

Step 1: Gather Refrigerator Specifications

A standard household refrigerator (e.g., 20–25 cu. ft.) typically has:

• Power Consumption: around 600 watts
• Voltage: in the U.S. — 120 V
• Current Type: Single-phase
• Safety Factor: recommended 1.25–1.5 to account for compressor startup current

Step 2: Enter the Data in the Calculator

• Voltage: 120
• Power: 600
• Safety Factor: 1.25 (or up to 1.5 for older refrigerators)
• System Type: Single-phase

Result:

So, a 10-amp circuit breaker is suitable for a dedicated refrigerator line — which is standard for residential use in Florida.

Conclusion:

A 10A breaker is generally sufficient for a refrigerator.
If the same circuit powers other devices like a microwave or countertop outlet, a 15A breaker may be necessary.
Always consider inrush current from the compressor — especially on older models. In such cases, a 15A slow-blow breaker is a safer choice.

Need the right breaker size?
Try our new online Circuit Breaker Size Calculator
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