Ordering custom fly screens online can feel slightly intimidating at first. The biggest question most people have sits right at the beginning: How do I measure for fly screens?
The truth is far less stressful than it seems. Knowing how to measure windows for fly screens simply requires patience, a steady tape measure and attention to small details. Once you understand where to measure and how to record those numbers, the process becomes surprisingly straightforward.
Accurate measurements matter because custom screens are made to fit the exact dimensions you provide. When the numbers line up with your window or door opening, installation becomes quick and satisfying. The screen slides neatly into place, sits flush against the frame and starts doing its job straight away, letting fresh air move through your home while keeping insects outside where they belong.
Tools You Need Before Measuring
You don’t need a toolbox full of equipment to measure for fly screens. A few simple items will do the job perfectly.
Start with a steel tape measure. Steel tapes stay straight while you measure across wider openings, which helps produce more accurate readings. Soft measuring tapes tend to bend or sag, and that can lead to small inaccuracies.
Next, grab a notepad and pen. It might sound obvious, yet plenty of people measure a window, walk inside and realise they’ve already forgotten the numbers. Writing each measurement down immediately saves time and avoids confusion later.
Some people also like using their phone to take a quick photo of the window alongside the measurements. This helps keep everything organised when ordering multiple screens.
One small but important detail: record all measurements in millimetres. Custom fly screens are manufactured using precise measurements, and millimetres remove the guesswork that can happen with centimetres or inches. Even a difference of a few millimetres can affect how neatly the screen fits inside the frame.
Once your tape measure and notepad are ready, you can move on to the actual measuring.
How to Measure Windows for Fly Screens
Measuring a window opening takes only a few steps. The goal is to capture the true size of the recess where the fly screen will sit.
Start with the width. Place the tape measure inside the window frame and stretch it from one inner edge to the other. Measure across the top, middle and bottom of the opening. Window frames sometimes shift slightly over time, which means the width may vary by a few millimetres.
Write down all three numbers, then select the smallest measurement. That figure represents the narrowest point of the opening, which prevents the finished screen from catching or jamming during installation.
Next, measure the height. Position the tape vertically inside the frame and measure along the left side, centre and right side of the window recess. Again, note all three measurements and keep the smallest one.
These two final numbers (the smallest width and smallest height) represent the most reliable dimensions for your fly screen.
How to Measure Up Fly Screens for Windows in Different Frame Types
Not all windows share the same design, and the frame style can influence where measurements should be taken.
The two most common approaches are inside mount and face fit installations.
An inside mount screen sits neatly within the window recess. This is the most common setup for aluminium windows and many modern homes. Measurements for this style come directly from the internal edges of the frame, exactly as described in the previous section.
A face fit screen sits on the outer surface of the frame rather than inside it. This approach works well for older timber windows or openings without a deep recess. Instead of measuring inside the frame, measurements are taken across the flat face where the screen will attach.
Frame material can also affect the measuring points.
Aluminium windows typically have clean internal recesses, making them easy to measure. Timber frames sometimes include decorative edges or slight variations in depth, so it helps to measure carefully along the flattest internal surfaces. Sliding windows require attention to the track area so the fly screen has enough clearance to move smoothly.
Taking a moment to observe the frame before measuring helps identify the correct mounting style and measurement points.
How to Measure for a Fly Screen Door
How to measure for a fly screen door follows a similar process to windows, although the larger opening makes careful measuring even more important.
For hinged doors, start by measuring the width of the doorway from the inside edge of one frame to the other. Take measurements at the top, middle and bottom, then record the smallest number.
Next, measure the height from the threshold or floor level up to the underside of the top frame. As with windows, measure along both sides and through the centre before selecting the smallest measurement.
Sliding screen doors require attention to the track area. Measure the width of the door opening where the screen will slide and the vertical distance between the top and bottom tracks. The tape measure should sit snugly within the track recess so the measurement reflects the true opening.
One common mistake with doors involves measuring the existing screen door rather than the actual frame opening. If the old screen has warped or shifted over time, those numbers may not represent the real space available.
Always measure the frame itself for the most reliable result.
Common Mistakes When Measuring for Fly Screens
A few small measuring habits cause most sizing problems.
One of the most frequent issues involves rounding numbers. For example, a measurement of 924 mm sometimes becomes “about 925”. That single millimetre might seem minor, yet custom screens rely on precise dimensions.
Another common error comes from measuring only once. Window frames rarely remain perfectly uniform over time. Measuring multiple points across the frame reveals the narrowest dimension and prevents installation headaches later.
Some people also mix up the frame size and the opening size. The measurement required for a fly screen relates to the clear opening where the screen sits, not the outer edge of the window frame.
Taking careful notes and measuring each point slowly helps avoid these issues.
What to Do After You’ve Measured
Once all your measurements are written down, you’re ready to order your custom screens.
When ordering through Ezy Screens, the process involves entering the width and height for each window or door directly into the product page. The system uses those dimensions to produce a screen tailored to your opening.
Before completing the order, it’s worth doing a quick check. Compare the numbers in your order with the ones written in your notebook. This simple step catches accidental typing mistakes, especially when ordering several screens at once.
Some customers also like to label each measurement with the room name, which makes installation easier once the screens arrive.
Why Accurate Measurements Save You Time and Money
Correct measurements make everything easier.
A properly sized fly screen fits comfortably within the frame, sits flat against the edges and installs without trimming or adjustments. The entire process becomes quick and satisfying.
Incorrect measurements create the opposite experience. Screens that are slightly too large refuse to slide into the frame, while undersized screens leave visible gaps around the edges. Fixing those issues often involves replacing the screen entirely.
Spending a few extra minutes checking your measurements helps avoid those frustrations.
Ezy Screens simplifies the rest of the process by manufacturing custom screens based on the exact dimensions provided. When the measurements are accurate, installation becomes a straightforward DIY project that transforms your windows and doors into fresh-air entry points without inviting insects indoors.
Frequently Asked Questions
How do I measure for fly screens without removing the old screen?
Leave the existing screen in place and measure the internal window frame where the screen normally sits. Measure across the top, middle and bottom for width, then repeat the process vertically for height.
How do I measure windows for fly screens in millimetres?
Use a steel tape measure with millimetre markings and record the exact number shown on the tape. Avoid rounding the measurement up or down.
How much smaller should a fly screen be than the window opening?
Custom fly screens are typically manufactured slightly smaller than the opening to allow smooth installation. When ordering, simply provide the exact opening measurements and the manufacturer adjusts the final sizing accordingly.
Can I measure for a fly screen door by myself?
Yes. Most people measure doors alone by holding the tape measure against one side of the frame and extending it across the opening. Measuring slowly and writing each number down immediately helps maintain accuracy.
What if my window opening is not perfectly square?
This situation is quite common, especially in older homes. Measure the width and height in several places and use the smallest measurement in each direction. That number reflects the narrowest part of the opening and allows the fly screen to fit comfortably.
