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EV Charging Cost Calculator (UK)

UK EV charging cost calculator using April 2026 Ofgem cap rates and Octopus Intelligent Go off-peak tariffs. Per-session and annual running cost on a 7 kW wallbox plus solar PV offset.

Prepared by the Solar Calculator HQ editorial team. Review our formula, source and limitation standards.

EV Charging Calculator

Energy drawn from the source
50 kWh
Time to reach target
6 h 45 min
Cost on grid only
£14
Cost after solar offset
£7
Saving from solar: £7
Granny / 3-pin (2.3 kW): emergency only.
7 kW home wallbox: full charge in 8-11 h.
Rapid (50 kW) and ultra-rapid (150-350 kW): 20→80% in 25-40 min.

What this calculator returns

This calculator computes the actual electricity cost of running an EV in the UK on 2026 residential tariffs:

  1. Energy drawn from the meter (kWh) — what your DNO reads and bills, including charging losses
  2. Charge time — hours and minutes from start to target state of charge on your wallbox
  3. Per-session grid cost (GBP) — the pound amount on your bill at the entered tariff
  4. Per-session cost after solar PV offset — what the charge actually costs after self-consuming rooftop PV
  5. Solar savings — the value of self-consumed PV at retail rate

Edit the tariff to compare the Ofgem default cap, an Octopus Intelligent Go off-peak slot, an EDF GoElectric tariff, or a public Ionity rapid station. The cost figure scales linearly with tariff so the comparison is direct.

How the cost math works

energy_to_battery (kWh) = battery_kwh × (target% - start%) / 100
energy_drawn (kWh)      = energy_to_battery / efficiency
charge_cost (£)         = energy_drawn × tariff_per_kwh
solar_savings (£)       = charge_cost × (solar_pct / 100)
final_cost (£)          = charge_cost − solar_savings

Worked example for a 75 kWh battery, 20→80%, 7.4 kW wallbox, 27p/kWh Ofgem cap, 50% solar PV offset, 90% efficiency:

  • Energy to battery = 75 × 0.6 = 45 kWh
  • Energy drawn from meter = 45 / 0.90 = 50 kWh
  • Grid cost = 50 × £0.27 = £13.50
  • Solar savings = £13.50 × 0.50 = £6.75
  • Final cost = £6.75 per session

Annualised at 150 charging sessions a year (typical for an 8,000 mi/yr commuter), this household pays £2,025 grid-only at the Ofgem cap, or £1,012 with 50% solar offset. Switching to Octopus Intelligent Go at 7p/kWh and shifting overnight cuts the all-grid case to £525, and stacking solar self-consumption on weekends drops it to £350-400 a year.

UK tariff scenarios to test in the calculator

  • Ofgem default tariff cap (April-June 2026): 27p/kWh unit rate, 60p/day standing charge
  • Octopus Intelligent Go (off-peak 23:30-05:30): 7p/kWh — the EV-specific market leader
  • Octopus Go (off-peak 00:30-05:30): 8.5p/kWh
  • EDF GoElectric 35: 9p/kWh off-peak (00:00-05:00), 30p/kWh peak
  • OVO Charge Anytime add-on: 7p/kWh applied to EV-only charge sessions on smart charger
  • British Gas Electric Driver: 9.5p/kWh off-peak (00:00-05:00)
  • Public rapid (Ionity, BP Pulse, Gridserve, Tesla Supercharger UK): 50-80p/kWh

Plug each into the tariff field to see the per-session and annual cost shift.

What lowers UK EV charging cost

  • EV-specific off-peak tariffs — Octopus Intelligent Go is the dominant choice in 2026 (over 600,000 UK customers); requires a compatible smart charger (Ohme, MyEnergi Zappi, Hypervolt, Andersen)
  • Smart charging schedules — your wallbox shifts charging into off-peak windows automatically
  • Solar PV self-consumption April-September — domestic 4 kWp arrays in central England produce roughly 12 kWh/day in midsummer, enough to put 60-70% of a 75 kWh battery in directly
  • SEG export tariffs — Octopus Outgoing 15p/kWh, E.ON Next Export 16.5p/kWh, EDF Export+EV 5.6p/kWh — payments for surplus PV reduce the net household electricity bill
  • OZEV EV chargepoint grant — £350 toward a smart charger for renters and flat owners (extended through 2026)

What raises UK EV charging cost

  • Public rapid charging as a daily habit — 7-12x home off-peak cost
  • Standing charges — Ofgem cap is 60p/day; on a small EV consumer this can be 15-20% of the bill
  • Three-phase upgrade for 22 kW — £2,500-6,000 DNO connection cost rarely recovered for typical 8,000 mi/yr drivers
  • Charging during peak (16:00-19:00 weekdays) — many EV TOU tariffs have a steep peak rate of 30-45p/kWh

UK regulatory framework

  • BS 7671 18th Edition Section 722 — installation requirements for EV charging (Type A or Type B RCD; PME requires an earth electrode or PEN-fault detection)
  • Electric Vehicles (Smart Charge Points) Regulations 2021 — all new home and workplace chargers must be smart-capable with default off-peak charging and randomised delay
  • Energy Performance of Buildings (EPB) regulations — new-build homes require EV charge point readiness from June 2022

Pair this calculator with output, savings, and system cost

The output calculator returns MCS-style annual kWh figures for any UK postcode, the savings calculator translates that into bill offset on Ofgem-cap pricing, and the system cost calculator gives you a Checkatrade-grade install price. Together they size a solar + EV setup that covers household and transport electricity.

Sources

Frequently asked questions

How much does it cost to fully charge an EV in the UK in 2026?
At the April 2026 Ofgem default tariff cap of 27p/kWh, a 0-100% charge on a 75 kWh battery costs about £22.50 of electricity once 10% AC charging losses are included (the wall draws roughly 83 kWh). A 20-80% daily cycle costs about £13.50. Switching to Octopus Intelligent Go (7p/kWh from 23:30-05:30) drops the same 20-80% session to £3.50, and Octopus Go (8.5p/kWh from 00:30-05:30) sits at £4.25.
What is the average annual home EV charging cost in the UK?
An 8,000-mile-per-year UK driver in a 4 mi/kWh EV draws roughly 2,200 kWh from the wall annually after losses. At the Ofgem cap of 27p/kWh that is £594 a year — equivalent to about £62 a month. Switching to Octopus Intelligent Go and time-shifting to overnight cuts that to £155 a year, a saving of around £440 a year before any solar offset. Public rapid charging at 50p-80p/kWh would push the same mileage to £1,100-1,760 a year.
Is it cheaper to charge from solar PV or off-peak grid in the UK?
Direct solar self-consumption beats off-peak grid in summer but loses to it in winter. UK domestic PV produces 60-70% of annual output between April and September, so daytime EV charging in those months is essentially free at 0p/kWh marginal cost. November to February PV output is 10-15% of peak — overnight Octopus Intelligent Go at 7p/kWh is cheaper than holding battery storage for daytime EV charging. The optimum strategy is: solar daytime April-September, off-peak grid November-February.
Are public rapid chargers worth it for daily UK driving?
No — public rapid charging at 50p-80p/kWh costs 7-12 times the Octopus off-peak home rate. A 20-80% session costs £25-40 at a public Ionity, BP Pulse, or Gridserve rapid versus £3.50 at home overnight. UK EV drivers do 90-95% of their charging at home in 2026 (Department for Transport survey) and reserve rapid charging for trips over 200 miles. Apartment dwellers without home charging pay the public premium and have weaker EV economics overall.
Does UK VAT apply differently to home and public EV charging?
Yes — and it matters for the calculator. Home electricity attracts 5% VAT (domestic supply rate). Public EV charging attracts 20% VAT (HMRC ruling, although Fairfair Charging are challenging this). On a 50 kWh public session at a 60p/kWh advertised rate, VAT is roughly 10p/kWh of that price; on home electricity at the 27p Ofgem cap, VAT is about 1.3p/kWh. The home/public delta is partly tax structure rather than wholesale cost.

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