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EV Charger Supply Capacity Calculator

Estimate signed supply headroom, shortfall and equal per-charger EV charging allocation from a common supply current basis.

Inputs

Supply and coincident load

Range: 0–100,000 A

Enter the usable current limit at the same supply point and phase basis as the other currents. This is not inferred from voltage or a nominal main-switch label.

Range: 0–100,000 A

Use a defensible measured or calculated coincident peak at the same supply point and phase basis.

Range: 0–100,000 A

Include planned demand that must remain available after the EV allocation.

Range: 1–100

Used only to divide positive headroom equally; it is not a charger model or phase allocation.

Result

Total current allocated to EV charging (A)
25.00
Supply headroom after existing and reserved demand (A)
25.00
Equal share per charger (A)
12.50
Current shortfall (A)
0.00
Positive capacity remains for the entered charger count

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Estimate remaining service current for a new charger
  • Divide available current across multiple managed chargers
  • Estimate current available for EV charging before verifying supply, phase basis, demand and load-control behaviour under the applicable installation rules.

Related calculators

Estimate current available for EV charging before verifying supply, phase basis, demand and load-control behaviour under the applicable installation rules.