WireGaugeCalc Free calculator · NEC cited · works offline
Size Wire Ground Bar To Panel
size wire ground bar to panel is quick with WireGaugeCalc, since you enter the circuit or service rating and the tool returns the grounding conductor gauge.
The calculator reads the NEC sizing tables for grounding and bonding, so the gauge tracks the overcurrent device ahead of it.
You get the right ground bar conductor before you bond the panel.
Open the calculatorSmallest conductor whose ampacity meets the load, NEC Table 310.16. Field aid only, verify against the current NEC and your local authority having jurisdiction.
Grounding Conductor Size Follows The Breaker Rating
The equipment grounding conductor is sized to the overcurrent device, so a larger breaker calls for a larger ground.
Copper and aluminum have separate columns, so the calculator changes the gauge as soon as you switch material.
Because the ground carries fault current only briefly, it is sized to clear the fault, not to match the phase conductors.
What Sets The Ground Bar To Panel Conductor
Enter these to size the grounding conductor:
- Overcurrent device rating in amps
- Conductor material, copper or aluminum
- Equipment ground or grounding electrode conductor
- Service or feeder size if bonding the main
- Result as the minimum NEC grounding conductor gauge
One app for every NEC calculation
WireGaugeCalc keeps the calculations you reach for most in one place:
- Voltage drop and wire sizing for any run
- Conduit fill for EMT, PVC, and RMC
- Box fill and junction box sizing
- Ampacity and temperature derating
- Motor circuit and load calculations
- Conduit bend offsets and saddles
Built for the field, works offline
The whole app runs on your phone, so it keeps working in a basement, an attic, or a job site with no signal.
There is no account to create and nothing to load. Open it, run the number, and get back to work.
- No signup and no signal needed
- Answers in a tap, not a spreadsheet
- Same tool on phone, tablet, and desktop
Every result cites the NEC article
Each answer shows the table or formula it came from, so you can check the method and learn the code as you go.
That makes the app useful on the job and during exam prep, since the reasoning is right next to the number.
Switch the code year your job runs on
Jurisdictions adopt the NEC at different times, so you can match the calculation to the code in force:
- NEC 2017, 2020, and 2023 tables
- Copper and aluminum conductors
- 60, 75, and 90 degree C terminations
- Single-phase and three-phase systems
Run the number, then get back to work
Stop flipping through a paper book or hopping between calculator sites. Enter your values, read the code-cited answer, and move on. Free to use, no signup.
Open the calculatorFrequently asked questions
Is the ground wire the same size as the circuit conductors?
Usually no. The equipment grounding conductor is sized to the breaker rating from the NEC table, so it is often smaller than the phase conductors on the same circuit.
Does upsizing the phase conductors change the ground size?
Yes, when you increase the ungrounded conductors for voltage drop, the equipment grounding conductor must be increased proportionally. Confirm the proportional increase against the current NEC and your local authority having jurisdiction.
Is WireGaugeCalc free to use?
Yes. Every calculator is free to run with no signup. A paid tier adds saved projects, PDF reports, and extra code years, but the core math stays free.
Does it work without internet?
Yes. The app runs on your device, so it keeps working with no signal on a job site, in a basement, or in an attic.
Are the results code accurate?
Results follow published NEC tables and standard formulas, and each answer shows the article it came from. It is a field aid, not a stamp of approval, so verify against the current code and your local authority before you wire anything.
Which NEC code year does it use?
You can switch between NEC 2017, 2020, and 2023, since jurisdictions adopt the code at different times. Pick the year your job runs on.