Roof measurement
Find the building, outline each roof and get its plan area in square metres, with the perimeter and an optional pitch. Download the plan, or carry the outline straight into a quote.
Areas come from satellite imagery, so they are an estimate of the plan area. For a drawing you can rely on, a measured roof survey is the right tool.
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Your roof
- Plan area
- 0 m²
- Perimeter
- 0 m
- Roof areas
- 0
Surface area = plan area ÷ cos(pitch). Flat or low-pitched roofs: leave at 0.
Nothing is saved unless you go on to the quote form. Figures are an estimate of the plan area from satellite imagery.
These results are a guide only and don’t replace a survey or professional advice.
Convert a figure
For an area or length from a drawing in other units.
1 square foot is 0.0929 m². 1 foot is 0.3048 m.
How to use it
Find the building
Type the postcode or address. The map moves to the building and shows it from above.
Outline each roof
Click Draw a roof, then click each corner. Close the shape by clicking the first corner again, and repeat for any other roofs.
Read the figures
Each roof’s area appears as you draw, with the total and the perimeter. Add a pitch for a sloping roof, then download the plan or get a quote.
What it measures, and what it cannot
The tool measures the shape you draw on the imagery, so it is only as good as the outline and the photograph beneath it.
It measures
- The plan area of each outline, in square metres
- The perimeter of each outline, in metres
- Surface area for a pitched roof, from the pitch you enter
- Several roofs on one site, added together
It cannot see
- Overhangs, parapets and upstands, which an overhead photograph hides
- The pitch itself, which is why you enter it
- Rooflights, plant and other roof furniture that a survey records
- Anything built or changed since the imagery was taken
Questions about measuring a roof
How accurate is it?
The area is worked out from the outline you draw over satellite imagery, so it depends on how closely the outline follows the roof edge and how recent the imagery is. Treat it as an estimate of the plan area. Where a figure has to be right, such as for a tender, a measured survey draws the roof to scale.
Does it allow for a sloping roof?
Enter the pitch in degrees and the tool converts the plan area to surface area by dividing by the cosine of the pitch. Leave it at zero for a flat or low-pitched roof.
Can I measure more than one roof?
Yes. Draw each roof as its own outline. The tool lists them separately and adds them up, and the plan shows all of them.
Is anything saved?
No. The outlines stay in your browser and are lost when you leave the page, unless you go on to the quote form, where they are saved with your request.
What is on the plan I download?
An image of the map with your outlines, each roof’s area, the total, the perimeter and the address, for your own records or to send to a contractor.
Get the right survey for your roof
Whether you’re investigating a problem or planning ahead, we’ll help you choose the right survey for your roof. Get in touch for a free quote.
Free quote
A few details about the building and what you need to find out. It commits you to nothing.
Start your quoteAll measurements, calculations and estimates provided by Roofcheck’s online tools are for guidance purposes only and should not be relied upon as definitive or technically accurate. Results should be independently verified through a professional roof survey or assessment before undertaking any works or making decisions. Roofcheck accepts no liability for any loss, damage or costs arising from reliance on these results, to the fullest extent permitted by UK law.