Waterproof Motorcycle Cover Sizes and Fit Guide

Buying a waterproof motorcycle cover by guesswork or engine size alone is a fast route to a flapping, moisture-trapping disappointment. The correct fit starts with a tape measure and ends with a comparison against the brand’s own sizing chart. The good news: the process takes about five minutes and works the same for cruisers, sportbikes, adventure bikes, and scooters.

How To Measure Your Motorcycle For A Cover

You need four measurements, taken with the bike on its sidestand or centerstand, parked on level ground. A cloth tape measure works best for curves; a metal one is fine for straight runs.

• Length: from the front tire’s leading edge to the rear tire’s trailing edge — or to the rear top box or fender if that extends further and will contact the cover.
• Front width: across the widest point at the front — handlebars, mirrors, or fairing, whichever is wider.
• Rear width: across the widest point at the rear — seat, fairing, top case, or saddlebags, whichever is wider.
• Height: from the ground to the tallest point, typically the windshield, mirrors, or handlebars.

If you still have the bike’s registration certificate, check whether it lists dimensions you can verify by tape measure. Many do, and they’re a useful cross-check. But always confirm with the tape — stickers and manuals can be optimistic.

Reading Sizing Charts: Cover Dimensions Vs. Bike Dimensions

Here’s the trap that trips up most buyers: some charts list the cover’s dimensions, not the motorcycle’s. Dowco’s fitment guidance, for example, states plainly that the numbers shown are for the cover itself, so you should allow 1–2 inches of extra length and width when matching your bike to a size. Weatherall Plus takes the opposite approach: measure the bike carefully, then order a cover slightly larger than those dimensions.

The fix is simple. Check the fine print on the chart you’re using. If it says “cover dimensions,” add a couple of inches to your bike’s numbers before comparing. If it says “fits motorcycles up to,” match your numbers directly.

As a reference point, here’s how one manufacturer’s sizes break down across common bike categories:

The Accessory Problem: When To Size Up

Windshields, saddlebags, top boxes, fairings, and sissy bars all change the envelope your cover has to fit over. A bike that measures as a “Large” without hard luggage can easily become an “XL” once you account for bags that stick out 3 inches on each side.

Manufacturers consistently recommend sizing up when in doubt. Tourmaster’s chart explicitly carves out separate categories for sportbikes with saddlebags and touring bikes with luggage, and R&G Racing’s cover lineup splits Adventure, Cruiser, and Supersport shapes because their proportions differ so much. If your bike has any of these accessories, measure across the widest and tallest point including them — then order the next size up from your result if it lands near a boundary.

A cover that’s slightly too big gathers a little extra fabric, but a cover that’s too small strains at the seams, doesn’t reach the mirrors, and lets rain pool on exposed bodywork.

Ground Clearance And The Mistakes That Ruin A Cover

The ideal fit keeps the cover 3–6 inches off the ground. A cover that touches the pavement wicks moisture up from wet concrete, picks up grit that scratches paint, and generally acts like a mop. Weatherall Plus’s guidance is explicit: choose a size that leaves about 3–6 inches of clearance; if the cover drags, you’ve sized up too far.

• Buying by engine displacement. A 1200cc cruiser and a 1200cc adventure bike have completely different silhouettes. Engine size tells you almost nothing about cover shape.
• Ignoring accessories. Saddlebags and top boxes are the usual culprits, but a tall windshield on an otherwise standard bike also pushes you up a size.
• Mixing charts between product lines. A single brand can sell a “standard” line and a “premium” line with different sizing logic. Always match your measurements against the chart for the exact model you’re buying.

For bikes with unusual proportions — a stretched cruiser, a heavily modified ADV, a scooter with a giant top case — measure the widest and tallest accessory, not the base bodywork, and let that be your guide.

Once you have the right dimensions in hand, the best place to see the leading waterproof motorcycle covers for every bike style is our tested roundup, which compares ground clearance, materials, and real-world weather protection side by side.