Calculating a copper or aluminum wire & cable’s minimum bend radius is the smallest allowed radius the cable is allowed to be bent around an object.During installation, cables are bent or flexed in various environmental conditions (Sometimes bent way too far!). Furthermore, wires and cables are often bent around a curve in conduits or underground ducts during installation, and bending radius is an input that installers need to know in order to get the cable and wire correctly pulled on their job.
Below you will find the best resources on bending radius for wire and cable, including an easy-to-use chart for figuring out your minimum bend radius per the NEC and ICEA, and a step-by-step calculator/guide for making this determination for your current or upcoming project.
Be sure to bookmark this page as a tab on your computer or smartphone by saving to favorites so you can reference back to use this handy bend radius tool.
Also, please remember there are some specialized bending radius calculations for different cables types per ICEA that we will cover further below such as DLO cable. Additionally, we sell electrical wire & cable all over the world so wherever you are working on calculating minimum bend radius and getting ready to buy your wire & cable, we can get you exactly what you need.
Call 1-888-651-9990 or message us for your pricing now.
How to Calculate Minimum Bend Radius of Cable and Wire? (Step-by-Step Formula & Calculator Tool per the NEC & ICEA)
- 1st Step: First, determine your Cable Type (Types listed in Chart below)
- 2nd Step: Second, is your cable single conductor or multi-conductor?
- 3rd Step: Third, verify your Cables Voltage.
- 4th Step: Fourth, is your Cable Shielded or Non-Shielded (Depending on Type)
- 5th Step: Fifth, is your cable classified as a mining cable?
- 6th Step: Sixth, does your Cable have Metallic Armor (MC)?
- 7th Step: Seventh, cable type has been verified. Calculate Minimum Bend Radius using the formula in step 8.
- 8th Step: Eighth, get Min Bending Radius by taking your wire & cable O.D. Outside Diameter x Cable Multiplier shown in Minimum Bending Radius Chart below. (Wire O.D. x Multiplier, depending on Cable Type)
Minimum Bend Radius = Wire & Cable Outside Diameter (O.D.) x Cable Multiplier by Wire & Cable Type
Examples Calculating Minimum Bend Radius using step by step guide above and 1XTech® Bending chart below.
Example 1: First, using the Bend Radius chart/tool below we see that a single conductor wire/cable without a shield, and less than 1000V has a minimum bending radius of 8x overall diameter.
Specifically, if we want to calculate the Minimum Bend Radius for a single conductor 500 MCM CU 600V THHN with an outside diameter of 0.902 Inches we would use the bending radius chart below paired with the step-by-step guide above to determine that single conductor THHN is less than 1000 volts, 1C, non-shielded, not a mining cable, not an MC Cable.
With this in mind, we see that the graph says we would use the table for NEC 300.34 after making our determination.
Minimum Bend Radius for 500 MCM THHN is the O.D. of Wire (0.902 Inches) x Cable Multiplier of 8X O.D. (1. NEC 300.34 / Graph below ) = 7.216 (MBR) Minimum Bending Radius
More MBR calculation examples are listed below the graph for your reference.
DLO CABLE MINIMUM BENDING RADIUS
First of all, during installation, DLO cables are bent or flexed according to the installation requirements. DLO cables are often bent around a curve in conduits, trays, or underground ducts. To prevent cable damage, cable standards associations, such as the Insulated Cable Engineers Association (ICEA), set requirements for minimum bend radius. Moreover, as per ICEA S-75-381, the applicable minimum bending radius for non-shielded power cables without metallic sheaths or armor are:
- The DLO Cable Overall Diameter (O.D.) x 6 (Multiplying Factor Chart above))
COPPER THHN WIRE & CABLE MINIMUM BENDING RADIUS
First of all, during installation, THHN Wires and cables are bent or flexed according to the installation requirements. THHN/THWN-2 cables are often bent around a curve in conduits, trays, or underground ducts. Taking precaution, and to prevent cable damage, cable standards associations, such as the NEC, set requirements for minimum bending radius. Moreover, as per NEC 300.34, the applicable minimum bending radius for non-shielded power cables without metallic sheaths or armor are:
- The Overall Diameter (O.D.) x 8 Multiplying Factor (Chart above)
COPPER XHHW-2 WIRE & CABLE MINIMUM BENDING RADIUS
First of all, during installation, Copper XHHW-2 Wires and cables are bent or flexed according to the installation requirements. XHHW-2 cables are often bent around a curve in conduits, trays, or underground ducts. Taking precaution, and to prevent cable damage, cable standards associations, such as the NEC, set requirements for minimum bending radius. Moreover, as per NEC 300.34, the applicable minimum bending radius for non-shielded power cables without metallic sheaths or armor are:
- The Overall Diameter (O.D.) x 8 Multiplying Factor (Chart above)
![Minimum Bend Radius Chart [Calculate Wire & Cable Types Bending/NEC] (2024)](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/h8AAvMB+NzmkbcAAAAASUVORK5CYII=)