How we calculate savings

The goal

We want to give you the most accurate possible estimate of what you'd pay on a given plan based on your actual electricity usage — not the average Australian household. Plans can appear very different depending on whether you're a heavy user, a light user, or have solar panels. National averages mislead.

Step 1 — Extract bill data

We extract the following fields from your uploaded bill:

• Daily supply charge — in cents per day
• Usage (kWh) — peak and off-peak if available
• Billing period — in days
• Total bill amount — as a cross-check
• Tariff type — flat rate or time of use

If any field is missing, we note it clearly and use a stated assumption in its place.

Step 2 — Annualise usage

We scale your billing period to a full year:

annual_kwh = usage_kwh × (365 ÷ billing_period_days)

If your bill is 91 days and shows 412 kWh of usage, we estimate annual usage as: 412 × (365 ÷ 91) = 1,653 kWh per year.

Step 3 — Calculate annual plan cost

For a flat-rate plan:

annual_cost = (supply_charge_cents × 365) + (usage_kwh × usage_rate_cents)

If a discount applies (e.g. 15% pay-on-time), we apply it to the usage component only, not the supply charge — which is how retailers calculate it.

For a time-of-use plan, we split usage as follows:

• 55% peak usage (at the peak rate)
• 20% shoulder usage (at the shoulder rate)
• 25% off-peak usage (at the off-peak rate)

If your bill already shows peak and off-peak usage separately, we use those figures instead.

Step 4 — Calculate savings

We estimate your current annual cost from your bill (total amount × annualisation factor), then subtract each plan's annual cost to get estimated savings:

savings = current_annual_cost − plan_annual_cost

Step 5 — Confidence scoring

We assign a confidence score from 0–100% based on data quality:

• +25% if actual kWh usage is present on the bill
• +10% if exact billing period is confirmed
• +10% if daily supply charge is confirmed
• +5% if state is confirmed from the bill
• Base score: 50%

A 95%+ score means we had full data from your bill. Below 70% means we've had to estimate one or more key fields.

Limitations

These are estimates, not exact figures. Your actual bill with a new retailer may differ due to:

• Seasonal variation in your usage
• Conditional discounts you may or may not qualify for
• Rate changes by the retailer after you sign up
• Concessions or rebates you may be eligible for

We recommend using our results as a guide, not a guarantee.

Plan data

Our plan data comes from the Energy Made Easy CDR API — a public, government-operated data source maintained by the Australian Energy Regulator (AER). Plans are fetched in real time when you enter your postcode, so you always see the latest published rates. We query up to 28 retailers for plans matching your postcode and tariff type. Plans are ranked by estimated annual savings — never by commission.