for Electrical Engineers, Consultants and Contractors
Voltage Drop Calculator - Global with American & Metric Wire Sizes
This voltage drop calculator is based on resistance and reactance values provided in USA National Electrical Code (NEC) 2023 edition - Tables 8, 9, and ASTM International B193-16. It adds to our old (1995) calculator metric wiring sizes that were often requested by our international clients. The calculator may assist in planning electrical installations adhering to North American wiring standards while using local metric system wiring.
North American conductors ampacity data conforms to the NEC table 310.16 and CEC ampacity tables.
Metric conductor ampacities for 60°C, 75°C and 90°C rated wires were provided by Canadian manufacturer “Northern Cables”. "MC Group Inc." added the 70°C rating, common worldwide. These ampacities were verified on Ampacity/Cross-section charts to visualize and confirm alignment with the North American sources.
The resistance and reactance data for metric sizes is extrapolated from the NEC and ASTM B193-16 proportionally to the North American.
Note: The metric wiring ampacities displayed in the calculator are not listed/approved (to our knowledge) in any code. Since electrical codes and protection devices differ from country to country, this software shall be used only by a qualified person in conjunction with all applicable local codes and regulations imposed by Authority Having Jurisdiction.
This application provides voltage drop calculations just like the original Voltage Drop Calculator and provides the same functionality. If you do not use metric wire sizes, we recommend using the original software. There is no extra cost for this calculator if you have already purchased a license to use our software. Reminder: our licence never expires and updates are free.
For wires or cables provided from manufacturers that specify AC resistance and reactance data, this application provides an input field to enable alternate calculation. Due to cables compact size reactance values can be lower which affects calculations particularly for low Power Factor feeders.
Voltage drop is proportional to energy loss. With rising cost of energy, you may find the "Feeder Efficiency Tip" useful.
Productive
Helps select proper wire size with colour coding while taking insulation rating and ambient temperature into account. Produces calculation report for record. Estimates full load current of motors based on horsepower rating (HP).
Flexible
Enter and modify values in any sequence, use metric or imperial units, AC and DC. Calculates on the fly. Paste results to any text application or spreadsheet. Displays DC voltage drop for comparison with AC. Has built-in wire ampacity tables for US and Canada. Estimates feeder operating temperature and allows for setting the feeder resistance values closer to the actual operating temperature and see the effect on the voltage drop – useful when feeder size is increased above minimum code requirements.
Easy to Use
All terms and definitions are explained on screen. No manual necessary.
What's New
Specifies conductor parameters used in calculation, which is useful for verification. Has spaces for calculation with cable manufacturer parameters.