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Octopus Agile Savings Calculator UK

Estimate how much you'd save — or lose — switching to Octopus Agile from a flat tariff, by DNO region. Models load shifting, EV charging and heat pump usage against a typical Agile hourly rate curve.

#tariffs #evs #heat pumps

Interactive Octopus Agile savings calculator

Worked example

A 3-person household in London (region C) using 3,500 kWh/year on a flat 27p tariff, willing to shift 30% of their flexible load overnight:

Flat tariff annual cost
£1146
Agile annual cost (30% shift)
£1002
Annual difference
£143
Break-even shift
0%
Cheapest 6-hour window
0:00–6:00
Cheap-window average
14.7p/kWh

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Is Octopus Agile right for you?

  • Good fit: EV owner who charges overnight ; heat pump with a buffer tank ; home battery owner; solar + battery household ; anyone with a heat-retention storage heater.
  • OK fit: WFH household with schedulable dishwasher/washer/dryer willing to shift ~30% of load.
  • Poor fit: all evening cooking + TV + hot-water immersion, no shifting willingness, no smart appliances — you'll pay more than a flat tariff.
  • Watch-out: Agile prices spike during cold, still weather (low wind, high gas demand). Budget for a few £2+/kWh half-hours per winter unless you can turn off.

Frequently asked questions

What is Octopus Agile?
Agile Octopus is a time-of-use electricity tariff where the unit rate changes every 30 minutes, tracking wholesale prices with a cap at 100p/kWh. Cheap overnight and midday troughs (often 5–15p/kWh) can offset peak-rate spikes (often 30–45p/kWh between 4pm and 7pm). The more of your load you can shift away from peak, the more Agile saves you.
What does DNO region mean?
Your Distribution Network Operator region is a single letter (A–P) determined by where in the UK your home is — it's the second character of your MPAN on your electricity bill. Agile prices vary by region because the underlying distribution charges differ; southern regions (C, J, H, L) are typically slightly more expensive, Scottish and northern regions (N, P, F) slightly cheaper.
How accurate is the hourly rate curve?
This v1 uses an indicative UK average hourly shape from 2026 Q1 Agile data, scaled to each region's mean unit rate. It's accurate enough to tell you whether Agile is worth switching to for your profile, and to identify your cheapest typical hours. It won't capture live price spikes (e.g. storms, low-wind days) or the occasional negative-price "plunge" events that reward battery owners. A future version will pull live Octopus API data for a rolling 12-month backtest.
Does this factor in standing charges?
Yes. The calculator uses the daily standing charge for your current tariff and for Agile separately, so if Agile's standing charge differs in your region (usually it doesn't, but it can), you can enter both.
Should I get a battery for Agile arbitrage?
A home battery typically costs £4,000–£7,000 installed (5–10 kWh usable) and shifts ~5–10 kWh/day from peak to trough. At current Agile price spreads, that's roughly £200–£400/year of arbitrage saving, so pure-arbitrage payback is 10–20 years — slow. Combine with solar or a heat pump and the numbers tighten considerably. We'll add an explicit battery model in v2.

How this calculator works

This v1 models a typical Agile hourly-rate curve for your DNO region — an overnight trough around 11p/kWh, a morning ramp, a flat daytime, a 4–7pm peak around 38–45p/kWh, then an evening taper. Those rates are scaled around each region's mean unit rate with a small peak-hour uplift for southern regions. Your annual consumption is split into fixed load (priced at the 24-hour mean), shiftable load (priced at the mean of the cheapest 6-hour window), and optional EV/heat pump blocks with their own price bases. Standing charges are added separately for both the flat tariff and Agile.

The break-even shift % is the fraction of your flexible load you'd need to move into the cheapest window for Agile to match your current flat tariff's total cost. If your actual shifting is above that, you save; below it, you lose. For most UK homes on a 27p/kWh flat tariff, break-even is somewhere between 15% and 35% depending on region — which is low enough that many households who think they can't shift actually can. The exact flat-tariff anchor matters: our Ofgem price cap calculator shows what that flat rate is this quarter and the next.

What v1 doesn't model

  • Live pricing. We'll pull the Octopus public API in v2 and backtest against your real 12-month region history.
  • Battery arbitrage. A home battery that charges in the cheapest 3h and discharges during the 4–7pm peak isn't modelled — add roughly £200–£400/year for a 5 kWh battery.
  • Plunge pricing. Agile occasionally hits negative rates (storms, low demand). Battery and EV owners can actively profit from these; we'll add a plunge-event counter in v2.
  • Heat pump temperature profile. We assume a flat daytime distribution minus peak — real SCOP-weighted modelling against outside temperature is a v2 item.

UK-specific context

Agile is UK-only (Great Britain; Northern Ireland has different supplier market structure). Your DNO region is fixed by postcode — you can't change it by switching supplier. Agile has been running since 2018 and has a large, active community on the Octopus forum and Reddit's /r/OctopusEnergy, which is a good place to sanity-check model outputs against real bill data before committing.

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