Free NEC 314.16 Box Fill Calculator

Box Fill Calculator for Electricians

The most accurate free box fill calculator online. Calculate electrical box fill per NEC 314.16, including conductors, devices, clamps, and grounding. Ensure your installations are safe and code-compliant.

Box Fill Calculator

Calculate electrical box fill requirements per NEC 314.16

Box Selection

Box Volume (cu.in.)

18 cu.in.

Conductors
Devices & Fittings
ResultsCOMPLIANT
Fill Percentage100.0%

Total Fill Required

18.00 cu.in.

Box Capacity

18.00 cu.in.

Remaining Capacity

0.00 cu.in.

Volume Breakdown:

Conductors (4x)9.00 cu.in.
Devices (1x)4.50 cu.in.
Internal Clamps2.25 cu.in.
Grounding Conductors2.25 cu.in.

Why Use Our Box Fill Calculator?

The #1 free electrical box fill calculator trusted by electricians worldwide. Our box fill calculator simplifies complex NEC 314.16 calculations.

NEC 2023 Box Fill Updated
Our box fill calculator stays current with the latest National Electrical Code requirements including terminal blocks per 314.16(B)(6).
Instant Box Fill Results
Get accurate box fill calculations in seconds, with detailed volume breakdowns for every component.
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Mobile Box Fill Calculator
Calculate box fill on any device - perfect for on-site electrical box fill calculations.

How the Box Fill Calculator Works

Three simple steps to calculate electrical box fill per NEC 314.16

01

Select Box Type

Choose from standard electrical box sizes or enter custom dimensions for your box fill calculation.

02

Add Components

Enter conductors, devices, clamps, and grounding wires for accurate box fill calculation.

03

Get Box Fill Results

Instantly see if your electrical box meets NEC 314.16 box fill requirements.

Box Fill Calculator FAQ

Ready to Calculate Box Fill?

Ensure your electrical installations meet NEC 314.16 requirements with our free box fill calculator. Trusted by electricians nationwide.

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