Learn how to measure clear acrylic Perspex sheets for cut-to-size ordering, including frame checks, allowances and common mistakes.
Measure in millimetres
When ordering clear acrylic Perspex cut to size, measure in millimetres wherever possible. Millimetres reduce rounding errors and make it easier to enter accurate dimensions online. Use a tape measure that is straight and easy to read, and write down height and width clearly before placing your order.
Measure twice before ordering. For replacement panels, check the existing panel and the opening it fits into. Old panels can warp, chip or be the wrong size, so the frame measurement is often the safer reference.
Check whether the panel sits inside or over the opening
A panel that sits inside a frame needs a different measurement from a panel that covers the face of a wall, bench, display or opening. Inside-frame panels usually need a little tolerance so they can be fitted without forcing the sheet. Face-mounted panels may need extra overlap so fixings have enough space.
For splashbacks, covers and wall panels, check nearby obstacles such as power points, taps, handles, trim and shelves. If a panel needs notches or cut-outs, plan those before confirming the final size.
Allow for expansion and installation
Acrylic can expand and contract with temperature changes, so it should not be jammed tightly into a frame. A small amount of clearance helps the panel sit neatly and reduces stress. This is especially important for larger panels and areas that may get warm.
If you are using screws, do not drill too close to the edge and do not overtighten. If you are using adhesive, make sure the adhesive is suitable for acrylic and the surface you are fixing to.
Common measuring mistakes
The most common mistake is mixing up height and width. Always label your measurements and check the orientation before ordering. Another common issue is measuring only one side of an opening. Older frames and walls may not be perfectly square, so measure at more than one point.
It is also easy to forget the thickness. The thickness affects how rigid the panel feels, how much it weighs and whether it fits into channels or trims. Check both the face size and the available depth before ordering.
Order the panel online
Once your measurements are ready, order clear acrylic Perspex sheet cut to size from the product page. Enter the height and width, choose your thickness and review the final details before adding the panel to cart.
For larger orders, write down each panel size before you start. Grouping panels by thickness and use can make ordering faster and helps reduce mistakes when you are pricing a full project.
Clear Acrylic Perspex FAQs
Should I measure acrylic in millimetres or centimetres?
Millimetres are best for cut-to-size orders because they reduce rounding errors and make the final panel size clearer.
Should acrylic fit tightly inside a frame?
No. A small amount of clearance is usually better because acrylic can expand and contract with temperature changes.
Can I order more than one acrylic panel size?
Yes. Measure each panel separately, especially if the openings are old, uneven or slightly different from one another.