⚡️ Did you know? A better energy rating could save you $350–$1,500 a year on bills ⚡️🏠 Homes with higher NatHERS ratings sell for up to 10% more 🏠🌿 Australia's average home rating is just 2.9 out of 10 stars — find out yours 🌿⚡️ Did you know? A better energy rating could save you $350–$1,500 a year on bills ⚡️🏠 Homes with higher NatHERS ratings sell for up to 10% more 🏠🌿 Australia's average home rating is just 2.9 out of 10 stars — find out yours 🌿
Free NatHERS Estimator

NatHERS Calculator — Estimate Your Star Rating in 2 Minutes

Get a free NatHERS star rating estimate (0–10 stars) for any Australian home. Uses the same core inputs as the accredited tools — climate zone, insulation, glazing, and energy systems — without the cost or wait of a formal assessment.

Start the NatHERS Calculator Find an Accredited Assessor

What the NatHERS calculator does

The Nationwide House Energy Rating Scheme (NatHERS) is the Australian Government's standard for measuring how energy-efficient a home is. Every home is rated from 0 to 10 stars based on how much heating and cooling energy it needs to stay comfortable year-round, expressed in MJ/m²/year. Our calculator mirrors the inputs used by accredited NatHERS software so you can get a fast, free estimate before committing to a paid assessment.

Climate-zone aware

All 69 NatHERS climate zones supported — Sydney to Cairns, Hobart to Darwin. Your zone is the biggest driver of your rating.

0–10 star output

Get an estimated star rating on the same 0–10 scale used by AccuRate, FirstRate5 and BERS Pro — the three accredited NatHERS engines.

No signup, no cost

Free forever. No email required to see your estimate or your top three recommended upgrades.

NatHERS calculator vs official NatHERS rating

Our calculatorAccredited NatHERS rating
CostFree$300–$600
Time~2 minutes5–10 business days
SoftwareSimplified estimatorAccuRate / FirstRate5 / BERS Pro
Issues a certificateNoYes — registered with CSIRO
Accepted for council / BASIX / sale disclosureNoYes

Use the calculator first to understand where your home sits. When you need a certificate — for a build, renovation, BASIX, or property sale — book an accredited assessor via our national assessor directory.

What inputs does a NatHERS calculator need?

  • Climate zone — postcode-based; the single biggest factor.
  • Building type, age, floor area & stories — drives the heating/cooling load.
  • Orientation & shading — north-facing living areas score better in southern Australia.
  • Insulation R-values — ceiling, walls, floor.
  • Glazing — single, double, low-E.
  • Heating, cooling, hot water & solar — moves your rating significantly.

Ready to estimate your NatHERS rating?

Answer 14 quick questions and get your estimated star rating plus the three upgrades most likely to lift it.

Open the Free Calculator

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