Not Sure What Skylight You Have?
Most skylights don’t have a brand or model. Start with the guides below to identify your skylight size.
| How to Identify Your Skylight Part
Most skylights don’t have a brand or model number. The correct replacement is identified by part type, shape, photos, and measurements.
Start by choosing the part you are replacing — dome, diffuser, shaft, surround, flashing or kit. Each part is measured differently, so follow the matching guides below.
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Use these quick guides to identify your skylight size
Identify your skylight size
Identify your skylight size from inside
No Ladder? Idenitfy it from the ground
Why your measurements may not match
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Measurements don't match?
Flanges can be trimmed differently
No Ladder or roof access?
Measure from the inside
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| Identification Success Stories
Helping Australians find the right skylight parts since 2009.
| What Skylight Part Are You Replacing
Most skylight repairs only require replacing one part. In most cases, this will be either the roof dome or the ceiling diffuser.
Identify which part you need below, then confirm your size before ordering.
How to Idenitify a Skylight Dome (Roof)
A replacement skylight dome is usually identified by the shape, base style, fixing method, and edge-to-edge dome measurement.
- Measure width and length of the dome (or diameter for round domes)
- Confirm the shape of the dome (round, square or rectangular)
- A photo alongside your measurements helps ensure accuracy
For a step-by-step guide, see our Skylight Measuring Guide.
Not sure? Use our Product Identifier form below and we’ll confirm the correct size for you.
How to Identifiy a Skylight Diffuser (Ceiling)
A skylight diffuser is identified by its shape, ceiling opening, frame style, and visible diffuser size.
- Measure width and length of the diffuser (or diameter for round diffusers)
- Confirm the diffusers shape (square, rectangular or round)
- A photo of the diffuser or ceiling opening helps ensure accuracy
For a step-by-step guide, see our Skylight Measuring Guide.
Not sure? Use our Product Identifier form below and we’ll confirm the correct size for you.
| Product Identifier
| What Happens Next
Once submitted, we’ll review your photos and measurements to identify the correct replacement part.
- We review your photos and measurements
- We identify the correct skylight part
- We confirm the best match before you order
If we need more details, we’ll contact you — no guesswork, no risk of ordering the wrong part.
| Skylight Identification FAQs
How to identify your skylight dome
Measure the base (edge-to-edge) of your existing skylight dome — not the height.
- Measure width and length (or diameter for round domes)
- Confirm the shape (round, square or rectangular)
- A photo alongside your measurements helps ensure accuracy
For a step-by-step guide, see our Skylight Measuring Guide
Not sure? Use our Product Identifier form above and we’ll confirm the correct size for you.
How to identify your skylight diffuser
- Measure the ceiling opening where the diffuser sits — not the overall panel size.
- Measure width and length (or diameter for round diffusers)
Confirm the shape (square, rectangular or round)
A photo of the diffuser or ceiling opening helps ensure accuracy
For a step-by-step guide, see our Skylight Measuring Guide
Not sure? Use our Product Identifier form above and we’ll confirm the correct size for you.
How do I identify what skylight I have?
Start by identifying which skylight component you are replacing. The most common parts that require replacement are the skylight dome on the roof or the skylight diffuser inside the ceiling. Once the part has been identified, measuring the skylight opening or panel size will help determine the correct replacement. Looking at the shape of the dome or diffuser and taking a few simple measurements will usually narrow down the correct skylight part.
What is the most common skylight size?
Many residential skylights installed in Australian homes follow common sizes such as 300mm, 400mm, 455mm and 500mm. Among these, 455mm skylight diffusers are one of the most frequently encountered sizes, particularly in hallways, bathrooms and kitchens where skylights are commonly installed.
Can I replace just the skylight dome?
Yes. In many cases the skylight dome can be replaced without replacing the entire skylight unit. If the dome has been cracked, become britte or damaged by hail, replacing the dome is usually the quickest and most cost effective repair. As long as the skylight shaft and flashing are still in good condition, a replacement dome will restore the skylight’s weather protection and light transfer.
Can I replace just the skylight diffuser?
Yes. The skylight diffuser can normally be replaced on its own without replacing the rest of the skylight. If the diffuser has become yellowed, brittle or cracked, installing a new diffuser can restore the appearance of the skylight and improve how light is distributed throughout the room.
How do I measure a skylight dome?
Measure the base of the skylight dome where it sits on the skylight frame. For round domes measure the diameter across the centre, and for square or rectangular domes measure edge to edge across the base. The internal diameter of the dome base is often the most important measurement because it determines the size of the skylight opening the dome is designed to cover.
How do I measure a skylight diffuser?
Remove the diffuser panel and measure the diameter for round diffusers or the edge-to-edge width for square diffusers. If the diffuser is damaged or missing, measuring the ceiling opening or skylight shaft size will usually provide a reliable guide to the correct replacement diffuser size.
What should I do if I cannot identify my skylight?
If you are unsure which skylight part you need, the easiest solution is to send us a photo of your skylight along with any measurements you have taken. Photos of the dome, diffuser, ceiling frame or skylight shaft opening often reveal details that help confirm the correct replacement part before ordering.
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