To measure a windshield for a sun shade, use a tape measure on the outside of the vehicle to capture the total width and total height of the glass, then compare those numbers to the manufacturer’s size chart or confirm your vehicle’s exact model for a custom-fit shade.
A sun shade that’s too small lets heat pour in; one too large won’t stay up. Getting the measurement right takes about two minutes with a tape measure, and the steps are the same whether you drive a sedan, SUV, or truck.
Measuring for a Universal Sun Shade
Take the tape measure to the outside of the windshield. Measure the furthest left edge of the glass to the furthest right edge for the width. Then measure from the bottom edge straight up to the top edge for the height. Write both down to the nearest quarter-inch. Then find a high-quality, recommended sun shade for your SUV or vehicle size and check its size chart against your numbers.
Why measure outside: the glass curves inward, and interior trim covers outer edges. Measuring from the driver’s seat almost always results in a shade too narrow. If measured width matches the product’s width, the shade will likely fit. Also check the cutout for the rearview mirror — if that notch isn’t positioned correctly, the mirror will push the shade away from the glass.
Using a Template for a Custom DIY Shade
For a fully custom shade, a rectangular measurement isn’t enough. Grab butcher paper, newsprint, or taped grocery bags. Place it on the outside of the windshield and hold it with wiper arms or tape loops (never on paint). Trace the glass edge along the rubber seal. Cut on the solid line (glass edge), not the dotted inner line — cutting the dotted line leaves the shade too narrow.
Common Measurement Mistakes That Ruin the Fit
- Measuring from inside the car: The interior edge is narrower than the exterior, guaranteeing a shade too small.
- Rounding up on the height: For a custom shade, rounding up makes it too tall, leaving a gap at the bottom.
- Skipping the mirror notch check: Measure the distance from the top of the glass down to the mirror mount and compare to the shade’s cutout location.
How to Install It So It Stays
For accordion shades: open the shade inside the car. Slide the bottom edge onto the dash where it meets the windshield. Press the upper edge against the glass until the top notch fits around the mirror. Pull sun visors down and press them toward the windshield. To remove, flip visors up, pull upper edge toward you, maneuver around the mirror, and fold. Store in its pouch.
For window shields: align bottom edge to dash line, press shield close to glass, then repeat for top corner. Sun visors do the holding. A well-measured shield stays in place all day.
FAQs
Can I measure the windshield from inside the car?
You can, but the result will likely be wrong. Always measure from the outside for a reliable fit.
What if my measured width doesn’t match any size chart exactly?
Choose the next size up, not down. A slightly wider shade can be positioned correctly; a too-narrow one leaves gaps.
Do I need a separate shade for the rear window?
Yes, if your goal is blocking heat from the entire cabin. Measure those windows the same way — outside, width and height.
References & Sources
- Car and Driver. “Window Shield for Car.” Covers installation steps, measurement guidance, and common mistakes for universal shields.
- Covercraft Support. “How do I know if the Sun Shade will fit my vehicle.” Official documentation on measuring outside the vehicle and checking mirror notch positioning.
- Types Auto Support. “How do I know what size shade will fit my vehicle.” Instructions for creating a paper template and avoiding sizing errors for custom shades.