Clearlane · Charger size & circuit
Home EV charger size calculator
Answer what size EV charger do I need from your miles and overnight hours — then choose between 32 A, 40 A, and 48 A Level 2. See a continuous × 1.25 breaker planning heuristic, compare hardwire vs NEMA 14-50, and shortlist chargers — educational only, not electrical advice.
After you pick an amp path, estimate Level 2 install cost & payback or confirm panel headroom.
Product · Charger size
Your driving & plug-in scenario
Defaults work out of the box. Adjust miles, efficiency, or hours — recommended continuous amps update live.
Try a scenario
Hours the car is plugged in and allowed to charge
Recommended continuous amps
Educational Level 2 planning at 240 V — not electrical design. How we size.
Continuous amp tier
32 A
32 A · 40 A · 48 A shortlist
- Daily energy need
- 9.4 kWh/day
- Avg power needed
- 1.18 kW
- Raw continuous (buffered)
- 5.4 A@ 240 V
- Charge-time sanity check
- ~1.2 hto replace session energy at 32 A
Suggested breaker (heuristic)
40 Adouble-pole · planning heuristic
32 A × 1.25 = 40 A → common 40 A breaker.
Common planning pair: 32 A continuous EVSE with a 40 A double-pole breaker (continuous × 1.25 heuristic). This is not a wire size schedule — conductor ampacity, temperature rating, conduit fill, GFCI/AFCI, and disconnects are decided by a licensed electrician and your AHJ.
Hardwire vs NEMA 14-50
Hardwire or NEMA 14-50 both work
At 32 A continuous, either a plug-in NEMA 14-50 EVSE or a hardwired wall unit can work. Prefer NEMA 14-50 for portable / multi-bay flexibility; hardwire for a dedicated permanent install.
What drives your number
- More daily miles or lower mi/kWh → higher continuous amp tier.
- More plug-in hours → lower amp needed for the same miles.
- Onboard AC limits can make a higher-amp EVSE pointless for charge speed.
- Panel headroom may still block the circuit even if amp math “works” — check the panel load calculator.
Amp-path charger shortlist
Example Level 2 units near your 32 A continuous path. Illustrative — not for sale via Clearlane. Product links coming soon — always verify UL listing and local code with your electrician.
Affiliate / referral disclosure: we may earn a commission if you request quotes or purchase through marketplace links. That does not change your price. Linked installers and merchants are independent — not Clearlane contractors.
How we size Level 2 continuous amps
Miles → energy → amps
Daily kWh ≈ miles ÷ mi/kWh. Average power needed ≈ session kWh ÷ plug-in hours. Raw continuous amps ≈ (kW × 1000) ÷ 240 V, then we add a small buffer (default 10%) before rounding up.
Standard 32 / 40 / 48 tiers
We recommend the next common continuous amp tier at or above your buffered need. Optional onboard AC limits can cap usable speed — a higher-amp EVSE will not charge faster than the car accepts on AC.
Breaker × 1.25 heuristic
Continuous load planning often uses nameplate × 1.25, mapping 32→40, 40→50, and 48→60 A breakers homeowners see on quotes. That is a heuristic — not wire sizing and not permission to install.
Assumptions
- Level 2 at a fixed 240 V assumption (not user-editable in v1).
- Defaults: ~33 mi/day (~12,000 mi/yr), 3.5 mi/kWh, 8 h plug-in, 10% buffer, 7 charge days/week.
- Fewer charge days/week packs weekly miles into each session (higher kWh per night).
- Onboard presets are illustrative labels only — verify against your owner’s manual.
- Panel capacity is out of scope here — use the panel load calculator.
FAQ
What size EV charger do I need — 32A, 40A, or 48A?+
It depends on daily miles, vehicle efficiency (mi/kWh), and how many hours you can leave the car plugged in overnight. This calculator converts that into raw continuous amps at 240 V, then rounds up to the next common Level 2 tier (32 / 40 / 48 A). More miles or fewer plug-in hours push you higher; long overnight windows often keep you at 32 or 40 A.
What breaker size goes with my continuous amp charger?+
EV charging is typically treated as a continuous load, so a common planning heuristic is continuous amps × 1.25. That maps roughly to 32 A → 40 A breaker, 40 A → 50 A, and 48 A → 60 A. This is educational planning only — not a code-compliant circuit design or wire schedule. A licensed electrician and your AHJ decide the real circuit.
Should I hardwire or use a NEMA 14-50 receptacle?+
NEMA 14-50 plug-in paths are often planned around ~40 A continuous on a 50 A circuit and suit portable / garage flexibility. Hardwired EVSE is common for permanent wall units and is usually preferred for 48 A continuous. Confirm receptacle, cord, and circuit ratings with an electrician.
What is an onboard AC charger limit?+
Many EVs cannot accept more AC amps than their onboard charger supports (often around 32 A or 48 A depending on model and configuration). Buying a 48 A EVSE will not charge faster than that onboard limit on AC. Presets here are illustrative — always verify in your owner’s manual.
Is this calculator code-compliant electrical design?+
No. Clearlane provides educational planning heuristics for US homeowners. It is not a permit calculation, wire sizing schedule, contractor bid, or substitute for a licensed electrician and your local authority having jurisdiction (AHJ).
Important disclaimer
This tool provides an educational estimate only. Amp, breaker, and circuit figures are common planning heuristics — not code-compliant design, wire schedules, or permit-ready analysis. Install cost figures are planning ranges anchored to public market articles — not contractor bids. Local amendments, existing wiring conditions, continuous loads, diversity, solar interconnection rules, and equipment nameplates can change the result. Always consult a licensed electrician and your AHJ before adding an EV charger, heat pump, or other major load, or before upgrading a service. Clearlane does not claim partnerships with contractors and does not replace professional advice. Tax credits and rebates have eligibility rules — consult a tax professional. Outbound quote and product links may be affiliate or referral marketplaces — not Clearlane contractors.