"How many chargers do I need?" is one of the most common questions in commercial EV projects, and one of the easiest to answer badly. Install too few and you under-serve demand and pay to retrofit. Install too many and you tie up capital in hardware that ages before it gets used. The answer depends on your property type, your users, local EV adoption, and how much you want to spend upfront versus add over time.
The good news is that the question has a reliable structure. Get the structure right and the numbers follow.
The framework: two separate questions
The single most useful move is to split a question people usually conflate:
- How many chargers should you install now?
- How much electrical infrastructure should you build now?
The answer to question one should be conservative, based on current and near-term demand. The answer to question two should be larger, planning for where demand sits in five to ten years. Building infrastructure ahead of need and filling it with chargers over time (the make-ready approach) is almost always the right strategy, because conduit and panel work is the expensive, disruptive part, and hardware is the cheap, swappable part.
Estimating current demand
Office and workplace. Survey employees: "Do you own a plug-in vehicle, or expect to buy one in the next 12 months?" That gives a near-term number. A mid-to-high-adoption market (coastal metros, college towns) might show 10 to 20 percent interest; lower-adoption markets, 3 to 8 percent (illustrative, as of Q2 2026). A common workplace planning benchmark is one port per 10 to 15 parking spaces, then scaled to your actual survey result.
Multifamily. Use local EV adoption as a proxy. If 8 percent of households in your market own EVs, assume roughly that share of residents do. Treat it as a floor: EV owners self-select into buildings with charging once it exists, so demand rises after you install.
Retail and hospitality. Utilization matters more than a head count, because the lot turns over all day. A retailer with 200 spaces and a 3-hour average dwell might see 600-plus parking events daily. You do not need 600 chargers; you need enough that a visitor who wants to charge can usually find an open port.
Rules of thumb by property type
Use these as a starting point, not a substitute for your own demand estimate. Figures are illustrative rules of thumb (as of Q2 2026).
| Property type | Install now | Build infrastructure for |
|---|
| Office / workplace | 5 to 10 percent of spaces | 15 to 25 percent of spaces |
| Multifamily | 10 to 20 percent of spaces | 25 to 40 percent of spaces |
| Hotel | 10 to 20 percent of spaces | 25 to 40 percent of spaces |
| Retail (3+ hr dwell) | 2 to 5 percent of spaces | 10 to 20 percent of spaces |
| Fleet depot | 100 percent of vehicles | 100 percent plus reserve |
Note that code may set a floor above these. In several states, new multifamily construction must install chargers at a meaningful share of spaces and make a larger share EV-capable; California's CalGreen is the most aggressive, pushing toward one Level 2 receptacle per dwelling unit in many cases (as of Q2 2026). Where code applies, build to the greater of code and your demand estimate.
Planning for growth
EV adoption is uneven and has not moved in a straight line: national new-EV sales actually fell year over year in early 2026 after the federal purchase credit expired, while high-adoption states stayed far above the national rate (as of Q2 2026). That is exactly why you size infrastructure for a range, not a point estimate.
The multi-year demand estimate: current demand times a growth factor.
- Low-growth market: roughly 1.3 to 1.5 times
- Medium-growth market: roughly 1.5 to 2.0 times
- High-growth market (major coastal and mountain metros): roughly 2.0 to 3.0 times
Build infrastructure for the multi-year number. Install chargers for the current number. If your market's trajectory is genuinely uncertain, bias the infrastructure up (it is cheap to oversize conduit now) and the hardware down (it is cheap to add later).
Level 2 versus DC fast charging
Most commercial properties should start with Level 2 (208/240V, roughly 7 to 19 kW per port), which fits any location where users park two or more hours.
DC fast chargers (50 to 350 kW) make sense for:
- High-traffic corridor locations near highways
- Sites where users stay under an hour
- Fleet operations needing rapid turnaround
The cost gap is large. Level 2 ports commonly run a few thousand to around $12,000 per port installed, while DCFC runs roughly $75,000 to $150,000 per port installed (as of Q2 2026). That gap is why dwell time, not ambition, should pick the charging level.
A worked sizing example
60-unit multifamily building, 70 parking spaces, medium-growth suburban market.
- Survey and local data suggest about 9 percent EV ownership today, so roughly five to six residents need charging now.
- Apply a medium-growth factor of about 1.8 times for a three-to-four-year horizon: roughly 10 to 11 EV-owning residents.
- Install now: 6 Level 2 ports (covers current demand with a small buffer; about 9 percent of spaces).
- Build infrastructure for: about 16 to 20 ports (around 25 to 30 percent of spaces), via oversized conduit and a sub-panel sized for that load.
- Operating approach: load management so the six initial ports share available capacity, deferring any service upgrade until the build-out grows.
When demand rises, you pull wire through conduit already in the ground and mount hardware. No trenching, no second mobilization. The early decision to oversize the conduit is what makes every later expansion cheap.
The make-ready calculation
When you build the project budget, split infrastructure from hardware:
- Infrastructure (conduit, sub-panel, electrical capacity): build for full future build-out.
- Chargers: install for current plus one-to-two-year demand.
The incremental cost of upsizing infrastructure during the initial install is typically modest (commonly cited around 15 to 30 percent more than sizing for current chargers only). Adding infrastructure later, with re-trenching and new conduit runs, commonly runs two to four times the original infrastructure cost (rules of thumb, as of Q2 2026). The math almost always favors sizing infrastructure up front.
Common mistakes
Under-sizing infrastructure. Building for four chargers when you will eventually need twenty, then paying to trench and reconduit. This is the expensive mistake, because it hits the costly part of the project.
Over-installing chargers too early. Charger hardware has a useful life of roughly 8 to 12 years. Installing 40 ports when you need 8 means some hardware ages out before it earns its keep, and you have tied up capital that could have waited.
Ignoring early utilization data. New installations often sit at low utilization for 6 to 18 months while local EV ownership builds. That is expected. Do not read early low utilization as proof the install was a mistake; read it against your multi-year demand estimate.
Sizing to a vendor's quote instead of your demand. A vendor proposing a fixed package has no special insight into your tenants. Run your own demand estimate first, then test quotes against it.
Last factually verified: 2026-05-24 against ENERGY STAR EV charging benchmarks, the 2025 CalGreen and state multifamily code summaries, Qmerit and EVB 2026 cost guides, and CarEdge EV market-share data.
