Vehicle Magnet Size Guide: What Fits Your Door and How to Make It Last

The standard truck door magnet is 12×18 or 12×24 inches on 30 mil magnetic material, sized to sit inside the door’s flat area with at least an inch of clearance from body lines and handles. Fit beats size: a magnet bridging a curve or crease grips only at its edges, which is how magnets peel at speed. Measure the flat zone of your door first, then buy the largest magnet that fits inside it.

Key takeaways

• 30 mil is the working thickness for vehicle magnets; thinner sheet loses grip and conforms poorly at highway airflow.
• Common sizes: 12×18 for car doors, 12×24 for truck and van doors, 18×24 for large panels and tailgates.
• Full flat contact is the safety rule: every square inch should touch steel, no bridging over creases, moldings or rivets.
• Magnets only grip steel; aluminum panels, many hoods and some modern doors will not hold them at all, test with a fridge magnet first.
• Weekly removal and cleaning is required maintenance, for both grip and paint protection.

What size magnet fits which vehicle?

Measure the true flat zone, avoiding the character crease most modern doors carry mid panel. If the flat area is smaller than the listed guess, size down; the inch of margin matters more than the extra area.

What layout reads best on a moving door?

1. Company name and trade dominant, phone number second, everything else optional, mirroring the letter height rules: a 3 inch phone number reads from about 30 feet.
2. High contrast panel: a white or brand color field that separates from your vehicle paint.
3. Rounded corners, standard on printed magnets, resist edge lift at speed.
4. Match the design to your yard signs and estimates so the brand compounds, the same consistency argument as in job site signage.

How do you care for vehicle magnets?

• Remove at least weekly, ideally after wet drives. Wipe both the magnet back and the door with a soft cloth, let both dry, reapply.
• Never store folded or rolled tight; keep flat, print side up, away from heat.
• In freezing weather, warm the magnet indoors before applying; cold sheet is stiff and grips worse.
• Wash the vehicle normally with magnets off; pressure washing an edge is how car washes eat magnets.
• Expect years of service with care; UV printed and laminated faces outlast the typical vehicle lease.

When are magnets the wrong product?

Aluminum bodied trucks, curved doors and daily highway hauling all argue for cut vinyl decals or a partial wrap instead, the decision worked through in magnets vs decals for contractors. And for the trades, remember the magnet is one leg of a system with job site signs and estimate paperwork; the American Trucking Association’s finding that 91 percent of people notice vehicle graphics applies to whichever format your truck wears.

Order magnets that fit

The vehicle magnet builder takes any custom size, so a door with an awkward 13×21 flat zone gets a 12×20 magnet, not a compromise. Upload your logo and our team lays out the door design free. Smaller custom magnets handle fridge and giveaway formats. Most orders print in 24 hours with delivery options confirmed in the cart.

Frequently asked questions

What thickness should a vehicle magnet be?

30 mil magnetic sheet is the vehicle standard, balancing grip strength with the flexibility to sit flush on a door panel.

Will a magnet stick to my truck?

Only if the panel is steel. Test with any household magnet; aluminum doors, common on some modern trucks, will not hold magnetic signs.

How fast can you drive with vehicle magnets?

Normal highway speeds are fine with full flat contact on clean steel. Peeling risk comes from bridged creases, dirt under the magnet or damaged corners.

How often should I remove vehicle magnets?

Weekly at minimum. Clean and dry both surfaces before reapplying to protect the paint and preserve grip.