calcfig
USUKAU

Is It Worth Replacing Halogen Downlights with LED?

Swapping twelve 50 W halogen downlights for 9 W LEDs, used 4 hours a day, saves about $238.05 a year at 33.14 cents per kWh. At $10 a lamp ($120 in all) that pays back in about 6 months.

Try your own numbers

W

On the label or the bulb. Example values: a 50 W halogen and a 7 W LED.

W
h
$

Your own price. The starting figure is only a placeholder.

¢/kWh

Change the area above or type your own rate from your bill.

Saving per year$238.05
Payback6 months
Energy saved per year718 kWh
Net after 10 years$2,260.51

12 × (50 W − 9 W) × 4 h × 365 days ÷ 1,000 = 718.3 kWh a year. × 33.14¢/kWh = $238.05 a year. $120.00 ÷ $238.05 = 6 months.

Ignores price changes, bulb or appliance life and the time value of money. Heat from the old item may have been useful in winter.

Fig. 1 Twelve downlights, 50 W to 9 W, 4 hours a day.

Every formula is tested against worked examples. How we check

Hours a daySaving per yearPayback
1 h$59.512 years
2 h$119.031 years
4 h$238.056 months
8 h$476.103 months

Fig. 2 The same upgrade used for more or fewer hours.

Last checked 10/11/2026. Sources: Australian Energy Regulator: The Default Market Offer (tariff caps 2026-27); Essential Services Commission (Victoria): Victorian Default Offer price review 2026-27.

How the saving is worked out

Each downlight saves 50 − 9 = 41 W. Twelve of them for 4 hours on 365 days is 12 × 41 × 4 × 365 ÷ 1,000 = 718 kWh a year. At 33.14 cents per kWh that is $238.05 a year. The lamps cost $120, so $120 ÷ $238.05 is 6 months. The net gain over ten years is $2,260.51.

What is assumed. The rate is the Ausgrid usage rate from the AER Default Market Offer, shown on the rates page, not your own. Downlights are assumed to be 50 W halogen and 9 W LED. The wattages and the price of the new item are examples. Use the figures on your own bulbs, appliance label and receipt.

When the answer changes

Low-voltage halogen downlights often sit behind a transformer, which may need replacing, so add that to the cost. A licensed electrician is needed for any wiring change. At 1 hour a day the same swap takes about 2 years.

Common questions

Can I swap the lamps myself?

Changing a plug-in lamp is simple, but any change to wiring or a transformer needs a licensed electrician in Australia.

Is the DMO rate my rate?

Only if you are on a default offer in that area. Enter the usage rate from your own bill for a better answer.

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