Wire Nut Size Chart

Reference family: IDEAL Wire-Nut 71B, 72B, 73B, 74B and 76B. The rows below are common explicitly listed Cu/Cu combinations chosen for fast field reference; they are not every approved bundle. Missing rows are neither approved nor prohibited by omission—check the complete manufacturer listing. Source [1]

No match in this selected reference. Clear the filters or check the manufacturer’s complete listing.

Voltage note: 71B and 72B are 300 V maximum; 73B, 74B and 76B are 600 V maximum for the general-use rating shown here. IDEAL separately specifies up to 1,000 V maximum in signs and fixtures for the applicable higher-voltage models. Source [2]

Wire Nut Size Chart | Turn2Engineering | Verify the exact connector model and current manufacturer listing before installation.

1. Identify the conductor material. This reference is for the cited Cu/Cu combinations only.
2. Write down every conductor gauge and quantity. Example: 2 × #12 + 1 × #14 AWG copper.
3. Match the full bundle to the exact connector model. Do not assume that a gauge range or cap color means every combination in between is approved.
4. Use the model-specific strip and installation instructions. Follow the current product labeling when it differs from a general reference.

No universal rule makes every gray, blue, orange, yellow or red twist-on connector interchangeable. Color is useful for identifying a product within a particular manufacturer and series, but the exact model and listed conductor bundle are the decision points.

A printed gauge range is also not permission to use every wire count and every mixed-gauge bundle inside that range. Write the bundle explicitly—for example, 2 × #12 + 1 × #14 copper—and verify that complete combination. Source [1]

“Smaller conductor” means smaller copper cross section, so #18 AWG is smaller than #16 AWG even though its gauge number is higher. Follow the instructions attached to the exact product in hand if its labeling differs. Source [3]

The arithmetic sum of copper areas cannot establish connector approval. Bundles with similar total copper area can have different numbers of conductor interfaces, strand behavior and physical arrangements.

That is why this page does not collapse multiple conductors into an “equivalent AWG” and return a color. For a bundle not shown here, use the manufacturer’s complete listed-combination sheet and match every conductor in the exact model entry. Source [1]

Solid and stranded copper: The cited combination list permits solid and/or stranded copper unless a row is specifically marked otherwise. Some entries carry construction-specific notes, so check the exact bundle rather than assuming every variant is interchangeable. Source [1]

Aluminum: The cited Wire-Nut combination listing is Cu/Cu only and explicitly says not to use those combinations on aluminum wire. Aluminum or mixed-metal work requires a connector system specifically identified for that application. Source [1]

Wet, buried or other special locations: Do not extend this dry-location reference to a sealed, direct-burial, wet-location or otherwise special installation unless the exact connector system is identified for that service. Follow the current product instructions and applicable installation requirements. Source [3]

1. Shut off power and verify a safe condition before working on the circuit.
2. Confirm the connector model, conductor material, exact gauges, counts and any construction-specific restrictions.
3. Strip conductors to the length specified for that model and conductor condition.
4. Follow the connector’s assembly instructions. IDEAL states that pre-twisting is not required for this Wire-Nut series; do not generalize that statement to every connector design. Source [2]
5. Inspect the finished splice and ensure the enclosure has adequate space for the actual installation.

Making a larger splice? Use the Box Fill Calculator to check conductor, grounding, clamp and device volume in the enclosure.

Reference basis checked September 30, 2026. Manufacturer documentation controls over this summary. The page intentionally distinguishes selected listed combinations from catalog range examples and does not extrapolate an unlisted bundle from total conductor area.

1. IDEAL — UL Listed Wire Combinations, UL File E5238. Cu/Cu combination basis; use the current manufacturer-served version for the complete list.
2. IDEAL — Wire-Nut Wire Connector Specification Sheet. Model/color identification, voltage ratings, range examples, spring description and pre-twisting statement.
3. IDEAL — Wire-Nut Wire Connector Installation Instructions. Strip lengths, installation warnings and product-use limitations.