Time of use calculator: is a TOU tariff cheaper for you?
Short version: on Ausgrid, a time of use tariff beats a flat rate once less than about 22.5% of your power is used in the 3pm to 9pm peak. On Essential Energy the break-even is about 60.4%, so time of use suits nearly everyone. On Endeavour Energy the off-peak rate is higher than the flat rate, so shifting load out of the evening never wins on its own; you have to move it into the cheap 10am to 2pm window instead. Those three numbers are the whole decision, and they are worked out below from the published network windows and the regulated reference rates current August 2026. The calculator just does the arithmetic with your numbers instead of the averages.
Rates and windows checked: 14 August 2026. Next scheduled review: January 2027.
Work out your own number
TOU versus flat rate, per year
Nothing is stored and nothing is sent anywhere. It all happens on your own device. If you do not know your usage, leave the defaults: they are the regulated typical household for your network.
Estimate only. It uses the regulated reference rates below, and it assumes your peak share is spread evenly across the year. Your own bill is the real answer, and the section on reading your bill shows where to find it. The default daily usage is the regulator's typical household rounded to the nearest 0.1 kWh, so the flat figure here sits within a couple of dollars of the exact annual reference price quoted further down.
The peak windows, by network
These are the network windows, published by each distributor. They are what the poles and wires operator charges your retailer, and they are the reason your tariff has the shape it does. Full detail, including the seasonal rules and the controlled load options, lives on the time of use tariff guide, which is where these tables are maintained.
| Network | Peak | Cheapest window | Everything else |
|---|---|---|---|
| Ausgrid Sydney, Central Coast, Hunter |
3pm to 9pm every day, June to August and November to March. No peak at all in April, May, September and October. | No separate cheap window. Shoulder was merged into off-peak in 2024. | Off-peak |
| Endeavour Energy Western Sydney, Blue Mountains, Illawarra, Southern Highlands |
4pm to 8pm on business days only. Higher rate November to March, lower April to October. | Solar soak, 10am to 2pm every day. This is the cheapest power in New South Wales. | Off-peak |
| Essential Energy Regional and rural NSW |
Sun Soaker tariff: 7am to 10am and 3pm to 10pm, every day. Older peak, shoulder and off-peak tariff: 5pm to 8pm weekdays. | 10am to 3pm sits in the off-peak band on Sun Soaker. | Off-peak, and all weekend on the older tariff |
One thing worth knowing before you act on any of this: these are the network windows. Ausgrid says so plainly on its own pricing page, that retailers may apply different peak and off-peak times and charges from the network ones. So treat the table as the shape of your tariff, and your bill as the authority on the exact hours.
The rates the calculator uses
Every figure below comes from the Australian Energy Regulator's Default Market Offer for 2026-27, the final determination published 26 May 2026 and in force from 1 July 2026. That is the regulated cap for standing offers, so it is a fair, dated, public reference point. It is not a promise about your bill: most households sit on market offers priced under the cap. All figures include GST.
| Network | Flat usage | Peak | Off-peak | Solar soak | Daily supply, flat / TOU |
|---|---|---|---|---|---|
| Ausgrid | 33.14c | 60.20c | 24.04c | n/a | 166.23c / 176.41c |
| Endeavour Energy | 33.73c | 46.57c | 35.69c | 12.35c | 185.14c / 185.14c |
| Essential Energy | 35.01c | 42.12c | 24.14c | n/a | 272.22c / 272.22c |
A quick check that these are the right numbers: multiply the flat rate by the regulator's own typical usage and add the supply charge, and you land on $1,899 for Ausgrid, $2,328 for Endeavour and $2,604 for Essential Energy. Those are exactly the annual figures the AER published. The arithmetic on this page reproduces the regulator's, which is the point.
The verdict rule, without the calculator
If you take nothing else from this page, take the break-even. It is the honest one-line answer to "does TOU suit me", and it is different on each network because the gap between the rates is different.
| Network | TOU wins if your peak share is under | What that means in practice |
|---|---|---|
| Ausgrid | 22.5% of your usage | About 2.4 kWh a day out of a typical 10.7 kWh. A genuine decision: a normal evening household is above this line and loses, a shifted one is below it and wins. |
| Endeavour Energy | Never, on peak shifting alone | The off-peak rate of 35.69c is 1.96c higher than the flat rate of 33.73c. Even using zero power in peak, TOU costs more. The only way it wins is the 10am to 2pm solar soak window. |
| Essential Energy | 60.4% of your usage | Off-peak is 10.86c cheaper than flat, so almost every household is already under the line. TOU is the better deal for most regional customers without changing a thing. |
The Endeavour result is the one that surprises people, so it is worth stating twice: on the regulated reference rates, an Endeavour household that uses no electricity at all in the evening peak still pays more on time of use than on a flat rate. Shifting the dishwasher to 9pm does not fix that. What fixes it is running the heavy stuff in the middle of the day, where the rate is 12.35c against a flat rate of 33.73c. Moving one kilowatt hour a day into that window is worth about $78 a year, which is roughly twice what the same kilowatt hour is worth moved overnight.
What a shifted kilowatt hour is actually worth
The other way to think about it. Take one kilowatt hour a day, move it out of the peak window, and a year of that is worth:
- Ausgrid: about $132 a year per kWh per day. The peak rate of 60.20c is two and a half times the off-peak 24.04c, the widest gap in the state. This is where load shifting pays best by a distance.
- Essential Energy: about $66 a year per kWh per day, moving from the 42.12c peak to the 24.14c off-peak.
- Endeavour Energy: about $40 a year per kWh per day moved overnight, or about $78 a year per kWh per day moved into the 10am to 2pm solar soak window instead.
For scale: an electric storage hot water system is usually 5 to 8 kWh a day on its own, and a pool pump 3 to 5 kWh. Put those two on a timer on Ausgrid and you have moved something like 9 to 13 kWh a day, which on those numbers is the difference between TOU costing you money and TOU being clearly the better tariff. That is one afternoon of work with a timer or a smart switch, not a renovation.
A worked example, Ausgrid, no calculator needed
A Sydney household on the regulator's typical 3,900 kWh a year, which is 10.7 kWh a day. Flat rate costs them $1,899 a year. Here is time of use at different levels of evening usage:
| Peak share | In the 3pm to 9pm window | Flat | Time of use | Difference |
|---|---|---|---|---|
| 35%, heavy evening user | 3.74 kWh/day | $1,899 | $2,075 | $176 worse |
| 30%, typical | 3.21 kWh/day | $1,899 | $2,004 | $105 worse |
| 22.5%, break-even | 2.40 kWh/day | $1,899 | $1,899 | line ball |
| 15%, hot water and pool shifted | 1.60 kWh/day | $1,899 | $1,793 | $106 better |
| 10%, well shifted | 1.07 kWh/day | $1,899 | $1,722 | $177 better |
The span from top to bottom is about $350 a year on an identical house using an identical amount of power. Nothing about the house changed. Only when it used the electricity changed. That is the entire proposition of a time of use tariff, and it is also why the tariff is a bad deal for anyone who cannot move their usage: a shift worker home all evening, or a household where the peak load is simply the family being awake.
The cost almost nobody counts
On Ausgrid the regulated time of use tariff carries a daily supply charge of 176.41c against 166.23c on the flat rate. That is 10.18c a day, or $37.16 a year, before you have used a single kilowatt hour. It is a fixed handicap the usage savings have to clear first, and it is buried in the part of the bill nobody reads. Endeavour Energy and Essential Energy charge the same daily supply on both tariffs, so this one is an Ausgrid problem specifically. The calculator above includes it. A lot of the comparison tables online do not.
How to check this against your own bill
Ten minutes with your last bill will beat any estimate on this page, including ours.
- Find the tariff name. Usually on page two, near the usage summary. Words like "time of use", "flexible", "sun soaker" or "seasonal" mean you are already on TOU. "Single rate", "anytime" or "general usage" means flat.
- Find your rates. A flat bill shows one c/kWh figure. A TOU bill shows two or three, labelled peak, shoulder, off-peak or solar soak, each with the kWh used at that rate.
- Work out your peak share. Peak kWh divided by total kWh, on a TOU bill. That is the number the calculator asks for, and yours will be more accurate than our 30% default.
- Compare against the break-even above. Under the line for your network means TOU is working for you. Over it means you are paying for the privilege.
- Check the daily supply charge on both offers before you switch, not just the usage rates.
If your bill only shows one usage figure, you are on a flat rate and you cannot work out your peak share from the bill at all. That is the real limitation of this whole exercise, and it is worth being straight about: without interval data you are guessing at the single number the answer hinges on.
Where the guessing stops
Everything above uses averages. The 30% default, the typical hot water figure, the assumption your usage pattern is the same in February and July. They are reasonable averages, and they are still averages.
Your smart meter has the actual answer. It records your consumption in half hour or five minute intervals, which means your true peak share is a measured fact sitting in your meter data rather than something to estimate. Most people never see it, because the retailer's app shows a monthly bar chart and nothing more useful.
Getting at it is the thing we do: pulling your real interval data into a dashboard, laying your actual tariff windows over the top, and answering the two questions this page can only estimate. Did the tariff change actually cost you money, and what specifically should you shift. From there the shifting can be automated rather than remembered, so the hot water, the pool pump and the car charge run in the cheap window on their own.
This estimate used averages. Your smart meter has your real data, and we will set up the dashboard that shows it: your usage against your actual peak windows, a before and after verdict on any tariff change, and the shifting automations to go with it. See how the energy dashboard setup works, or tell us what your bill is doing and we will tell you straight whether the tariff is the problem.
Where this comes from
Every rate and window on this page is from a primary source, so you can check any of it rather than take our word for it:
- Ausgrid time of use pricing, for the 3pm to 9pm window and the April, May, September, October no-peak rule.
- Endeavour Energy Network Price List, section 6.1, for the 4pm to 8pm business day peak, the 10am to 2pm solar soak, and the November to March high season.
- Essential Energy Network Price List and Explanatory Notes, effective 1 July 2026, for the Sun Soaker and peak, shoulder, off-peak window tables.
- AER Default Market Offer 2026-27 final determination, 26 May 2026, for every cent per kilowatt hour and daily supply charge used here.
- AER, consumer rights and smart meters, for the two year consent protection on tariff structure changes after a meter replacement.
- Energy Made Easy, the regulator's own comparison site, if you want to shop offers after you know your peak share.
Frequently asked questions
Is a time of use tariff cheaper than a flat rate?
It depends on your network and how much of your power you use in the peak window. On Ausgrid, a time of use tariff beats a flat rate once less than about 22.5 per cent of your usage falls in the 3pm to 9pm peak. On Essential Energy the break-even is about 60.4 per cent, so time of use suits most households. On Endeavour Energy the off-peak rate is actually higher than the flat rate, so shifting load out of peak alone never wins; you have to move usage into the 10am to 2pm solar soak window. Rates current August 2026.
What are the peak times for Ausgrid, Endeavour and Essential Energy?
Ausgrid residential peak is 3pm to 9pm every day during June to August and November to March, with no peak at all in April, May, September and October. Endeavour Energy peak is 4pm to 8pm on business days only, with a cheap solar soak window from 10am to 2pm every day. Essential Energy on its Sun Soaker tariff charges peak from 7am to 10am and 3pm to 10pm every day. These are the network windows; your retailer can apply different times.
Does a smart meter put me on a time of use tariff automatically?
Not by itself, and since 1 December 2025 you get a say. If your retailer replaced your meter on or after that date, it cannot move you off a flat rate onto a time of use or demand tariff for two years without your explicit informed consent. That covers NSW, Queensland, South Australia, Tasmania and the ACT, and only while you stay with the retailer that installed the meter. After the two years it can change your tariff structure without consent, but it must give you at least 30 business days notice and show what your last 12 months would have cost on the new structure. If your meter went in before 1 December 2025, or you have since switched retailers, this may not apply to you. Separately, the network tariff your distributor assigns does default to time of use or solar soak on meter changes; that is a different thing from the retail tariff, which is the one that sets your bill.
How much can I save by shifting usage off peak?
On Ausgrid, moving one kilowatt hour a day out of the peak window is worth about $132 a year, because the gap between the peak rate of 60.20 cents and the off-peak rate of 24.04 cents is the largest in New South Wales. On Essential Energy the same one kilowatt hour a day is worth about $66 a year, and on Endeavour Energy about $40 a year. A hot water system or pool pump on a timer usually moves several kilowatt hours a day.
Why is the daily supply charge different on a time of use tariff?
On Ausgrid the regulated time of use tariff carries a daily supply charge of 176.41 cents against 166.23 cents on the flat rate, which is about $37 a year more before you use a single kilowatt hour. Endeavour Energy and Essential Energy charge the same daily supply charge on both tariffs. This fixed difference is easy to miss and it is why a small saving on usage can still leave you worse off overall on Ausgrid.
Are these the rates I will actually pay?
They are the regulated reference rates, not necessarily yours. The figures here come from the Australian Energy Regulator's Default Market Offer for 2026-27, which sets the price cap for standing offers from 1 July 2026. Most households are on market offers priced below the cap, and retailers may also apply different peak windows from the network ones. Use these as a starting point and then put your own rates in from your bill.
Related guides
- Time of use tariffs in NSW explained, the full guide to the windows, the seasons and the tariff types.
- Home energy dashboard setup, seeing your real usage against your real tariff.
- Home Assistant for a small business, the same automation approach applied to a workplace.