Example field question
Use this calculator when a design review or site issue requires a quick engineering check before a detailed manufacturer selection.
VoltCheck24 Engineering Calculator
Wire Size Calculator DC
Estimate DC wire gauge from load current, one-way cable length, system voltage, and voltage-drop target. Compare AWG and mm2 sizes for field wiring.
How to use this calculator
- Collect the values below from the equipment nameplate, data sheet, or field measurement.
- Enter values using one consistent unit system and use worst-case operating conditions.
- Review the result, margin, and engineering note before selecting hardware.
- Cross-check the result with the related calculator and save the review for your project record.
Input checklist
- DC load current
- One-way distance to the load
- AWG or mm2 conductor options
- Target voltage-drop limit
Common mistakes to avoid
Do not mix nominal values with measured worst-case values. Keep units consistent and include cable, temperature, duty, and derating assumptions where applicable.
Standards and validation
Review the result against local codes, IEC/NEC/NFPA/ISO practices when applicable, project specifications, and the latest manufacturer data sheet.
Formula and Inputs
Required conductor size increases as current and cable distance rise, because DC voltage drop follows I x R across the supply and return path.
Industrial Use Cases
Use this page when a search starts from the phrase wire size calculator DC, especially for control power, battery loads, and remote low-voltage devices.
Engineering Note
Do not select wire size from voltage drop alone. Check ampacity, insulation rating, terminal limits, overcurrent protection, ambient temperature, and installation method.
DC wire sizing workflow for global projects
DC wiring problems usually start with a simple question: will the load still receive enough voltage after current flows through a long conductor? VoltCheck24 treats wire size as a voltage-drop and verification workflow, not only a gauge lookup. Start with the real load current, one-way route length, system voltage, and acceptable voltage drop. Then compare the result with ampacity, fuse or breaker size, terminal limits, insulation temperature, and local code requirements.
DC source+Supply conductor resistance+Load current=Terminal voltage margin
| Use case | Common search intent | What to verify after voltage drop |
|---|---|---|
| 12V battery, RV, marine, LED | 12V wire size calculator, battery cable size | Fuse location, flame rating, vibration, wet or outdoor environment |
| 24V PLC, sensor, solenoid, IO-Link | 24V cable calculator, sensor voltage drop | Device minimum voltage, inrush current, shared returns, SMPS tolerance |
| Solar DC and off-grid wiring | solar DC cable size calculator, PV voltage drop | UV rating, connector current, temperature derating, PV code rules |
| International panel wiring | AWG to mm2, wire size calculator DC | AWG/mm2 conversion, terminal range, IEC or NEC project standard |
Important: voltage-drop calculators support preliminary sizing only. Final conductor selection must be checked against the latest local electrical code, manufacturer data sheets, protection coordination, and measured field conditions.
DC gauge selection
Use this page when the search starts with wire gauge or AWG. It is a sizing entry point, not a substitute for installation method, grouping, fuse, and terminal checks.
Worked field question: Example: compare AWG 20, AWG 18, and metric 0.75mm2 for the same load and distance. Keep one unit system in the project record.
FAQ
Why does DC wire size depend on distance?
Longer conductors have more resistance, so the same current creates a larger voltage drop at the load.
Is a lower AWG number larger?
Yes. In the AWG system, smaller gauge numbers mean larger conductor area and lower resistance.
Preliminary engineering reference only. Confirm final selections against current standards, project specifications, and manufacturer data.