---
title: "EV Charging Service Capacity & Transformer Calculator | Entogo"
description: "Free tool to estimate EV charging load, service capacity, transformer size and switchboard rating for commercial sites."
url: https://entogo.ca/tools/ev-charging-service-capacity-calculator/
lang: en
type: website
image: https://entogo.ca/og-cover.jpg
alternates:
  en: https://entogo.ca/tools/ev-charging-service-capacity-calculator/
  fr-CA: https://entogo.ca/fr/tools/ev-charging-service-capacity-calculator/
  fr: https://entogo.ca/fr/tools/ev-charging-service-capacity-calculator/
  es: https://entogo.ca/es/tools/ev-charging-service-capacity-calculator/
  ar: https://entogo.ca/ar/tools/ev-charging-service-capacity-calculator/
site: https://entogo.ca/
llms: https://entogo.ca/llms.txt
---

Home › Tools › EV charging service capacity & transformer calculator

Planning tool

# Commercial EV Charging Service Capacity & Transformer Calculator

Entogo's free calculator: estimate EV charging load, service capacity, transformer size, switchboard rating and EMS load-management scenarios for North American commercial sites. Tell us the chargers you plan to install and see whether your service can take them — under the NEC (US) or CEC Section 86 (Canada).

Estimate your site

## Describe the chargers and check your capacity.

Skip the existing-service step for a new-build estimate, or add it for a GREEN / YELLOW / RED verdict. Every result is shown on this page — no sign-up required.

Good to know

## EV charging capacity, transformers & code

Common questions about sizing service, transformers and load management for commercial EV charging — for the US (NEC) and Canada (CEC Section 86 / Ontario ESA).

- **Can my existing electrical service handle EV chargers?**: Enter the chargers you plan to install and your existing service rating and measured peak demand, and the calculator returns a GREEN / YELLOW / RED verdict: GREEN means the service has headroom, YELLOW means a compliant load-management system (EVEMS) can likely avoid an upgrade, and RED means a service upgrade is required. Results are a quick estimate for planning — double-check with your electrician and utility before building.
- **What size transformer do I need for an EV charging station?**: The calculator sizes the transformer from the code load divided by a design loading factor (0.80 by default) and rounds up to the next standard kVA. As a rough guide, four 150 kW DC fast chargers draw roughly 645 kVA of input and point to a transformer in the 750–1000 kVA range; six 32 A Level 2 chargers at 208 V point to about 75 kVA. Confirm whether the transformer is utility- or customer-owned with your utility / LDC.
- **How is EV charging load calculated under the NEC (Article 625 / 220.57)?**: Under the NEC, EVSE is a continuous load (Article 625), so the service/feeder calculation (Article 220, restructured into Article 120 in NEC 2026) applies a 7,200 VA per-EVSE minimum in the standard method and a 125% continuous-load factor for ampacity. The calculator follows this for the US profile; the exact provisions vary by adopted edition and occupancy.
- **How does CEC Section 86 handle EV charging load in Canada?**: Under CEC 2024 Section 86, EVSE is treated as a continuous load (86-302 via 8-104). Without an EVEMS the chargers are counted at 100% under Section 8 — the former demand-factor table (Table 38) has been removed and is not relied on. With a compliant EVEMS, the EVSE demand can be limited to the EVEMS maximum under 8-106(10)/(11) with the EVEMS meeting 8-500. In Ontario, existing-service capacity may be assessed under 8-106(9) using the LDC 12-month peak plus the EVSE, per ESA Bulletin 86-1-7.
- **Can EVEMS load management avoid a service upgrade?**: Often, yes. A listed/marked load-management system that monitors a compliant point can cap the EV load so the total stays within the existing service — frequently a far cheaper alternative to a service or transformer upgrade. The calculator compares the unmanaged code load against the EMS-limited load and highlights the capacity saved. The EMS only counts toward the code-managed figure when its listing and monitoring scheme are confirmed.
- **Is this a code-compliant load calculation I can submit for permit?**: No — it’s a free estimate for early planning, not a permit document. Use it to scope the project and sanity-check feasibility, then confirm the final numbers with your electrician and utility before ordering equipment or building.

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```

_Markdown twin of https://entogo.ca/tools/ev-charging-service-capacity-calculator/ — generated at build time from the same content as the HTML page. Company facts, catalogue index and contact: https://entogo.ca/llms.txt_