Southwire® Voltage Drop Calc vs DC Wire Sizer

Southwire's voltage drop calculator will help you determine the proper wire size for an electrical circuit based on the voltage drop and current carrying capacity of an electrical circuit. Determines wire size to meet specific voltage drop limits or calculates voltage drop for a specific conductor run. When sizing conductors, calculations limits wire size to voltage drop and NEC ampacity. Southwire's Voltage Drop Calculator is designed for applications using AWG and KCMIL sizes only.

Adding accessories (bilge pumps, electronics, solar, etc.) or upgrading batteries (AGM, Li, etc.) this year?  The #1 Cause of Boat and RV fires is DC wiring!  Undersized wires can damage equipment or cause fires.  The top-rated DC Wire Sizer calculates wire size for any DC voltage (ideal for solar in series). Plus lets you SAVE, EDIT, SUM, EMAIL and EXPORT the wire runs and material for your electrical plan, wire purchases, work orders, and records. And the Sizer Wizard option makes wire sizing easy for EVERYONE! Fast and safe wire sizing calculator for your next DC wiring project (battery, charger, inverter, trolling motor, stereo, and more). Designed with and for Marine Electronics Installers, Repair Services, Boat Builders, Surveyors, Do-It-Yourselfers, and Boat Owners. ONLY DC WIRE SIZER OFFERS these FEATURES: - Select any DC voltage and up to 500 amps - Results display wire size, VOLTAGE DROP (VD), and AMPACITY! - More granular “What if” analysis of ampacity & VD based on wire sizes & length - Choose from three methods of entering wire lengths for fast entry including separate positive/negative wire lengths (when different or negative is contact grounded, like a starter) - SAVE Wire Runs with the option to select or enter Wire Run & Project Name, wire type, wire color, status, and material source (Inventory or Buy) - EDIT Wire Runs including wire length, amps/watts, max voltage drop, insulations, inside/outside engine room, bundle, and the fields above. - SUMs active wire run lengths by size, type, and color to make purchasing easier and less expensive when by the reel (25’, 50’, 100’, etc.) - Select from a wire type list (e.g., primary, battery, safety, flat, duplex, triplex, mast, twisted, bilge, trailer, and solar cable) - Select marine standards (ABYC or ISO) - Change Unit of Measurement (Feet or Meters) in existing Wire Runs - Easy to use Sizer Wizard - Email and Export of Wire Runs and Raw Material MORE FEATURES: - Set default Wire Gauge (AWG, SAE, or MM2) - Set default Unit of Measure (feet or meters) - Select or enter Maximum Voltage Drop % - Select Bundle Size (1, 2-3, 4-6, 7-24, and 25+) - Select Insulation rating (60°, 75°, 80°, 90°, 105°, 125°, and 200°C) - Tap Inside/Outside Engine Room - Spin Amp/Watts and Wire Length for fast entry - Built-in Help and Technical Reference includes installation tips, connector types, color codes, tables (Voltage Drop, Ampacity, & Bundle), formulas (Power Triangle, Ohm's Law, etc.), recommended tools/books, and more. HERE’S WHAT REVIEWERS ARE SAYING: "The DC Wire Sizer is the most complete and comprehensive marine DC wire-sizing tool available. Developed for both marine professionals (the Wire Sizer Pro) and the occasional tinkerer (the Wire Sizer Wizard), the app determines the proper wire size, along with the voltage drop and ampacity by using the ABYC E-11 or ISO 10133 formulas and tables.” -  OnboardOnline (2013) "Stay organized by adding a wire description to the wire run and assign it to a project name (ie boat name, owner or work order). Mark the wire run as "Complete" or “Cancelled”, re-order wire runs within a project or move them between projects. Tired of adding wire runs in order to figure out what to purchase and how much? DC Wire Sizer sums the active wire runs for you by wire size (e.g. 8 AWG) and type (e.g. Safety Duplex, Battery Cable, and Primary Wire).” - marinabusiness (AU 2013) "If you're doing a lot of wiring on your boat, the app allows you to save the calculations with project names and wire type.  The app then can sum the length of the wire runs by wire type and size which can be used as a shopping list for your projects.  No other app offers these unique features and that's what makes it a winner.”  - i-marineapps (2013) "This is the best wire sizer program I have seen to date.  I can size and make a list at the same time also there is a better selection of amps and volts.” - Keith Herridge, Special Projects, Lyman-Morse Boatbuilding