What Are the Standard Dimensions for Tandem and Double Garages?

Unsure if your planned garage will fit your vehicles and gear? I will give you the reliable measurements I use on every job to ensure a perfect fit.

This article walks you through common widths and lengths for each style, practical tips for measuring your own cars and storage, and key differences between tandem and double designs.

With over a decade of hands-on garage planning and maintenance, I have helped homeowners avoid costly sizing mistakes and build functional spaces.

The First Step: Know Your Tandem From Your Double

Think of a tandem garage like a train and a double garage like a bus. In a tandem, your cars park end-to-end, one behind the other, like train cars on a single track. In a double, they park side-by-side, like seats on a bus.

This single layout decision impacts everything from your driveway shape to how you’ll actually use the space for the next 20 years. On a narrow, deep lot, a tandem garage often makes more sense for the driveway layout. But if you need to get either car out without moving the other, a side-by-side double is the only practical choice. I’ve walked into too many garages where a homeowner is frustrated because they didn’t think this through before the concrete was poured.

Visualizing the Space: A Quick Sketch Saves Headaches

Before you look at any standard dimensions, you need to understand your own needs. Grab a 25-foot tape measure-I keep a Komelon self-lock model in my tool bag for jobs like this-and a piece of graph paper.

1. Measure the length and width of your largest vehicle.
2. Add at least 3 feet to the length and 2.5 feet to the width. This extra space is for you to open the door without hitting the wall or another car, and to have room to walk around.
3. Now, sketch it on the graph paper. Use one square for every foot. Draw the cars, the walking space, and then think about where your garbage cans, workbench, or shelves might go.

This simple 15-minute exercise will show you the real size you need better than any generic chart ever could.

How Big Is a Tandem Garage? Standard and Minimum Sizes

Most homeowners ask me for the “standard” size right away. In my experience, a common, functional tandem garage is about 12 feet wide by 22 to 24 feet long, typically narrower than a one-car garage due to its layout.

A 12-foot width gives you enough room to open a car door comfortably next to a wall or storage shelves. The 24-foot length is the key. It lets you park two mid-size sedans, like a Honda Accord (about 16 feet long) and a Toyota Camry (about 16 feet), with a couple of feet of buffer between bumpers and the garage door. This size is ideal for most two-car garages.

“How long is a tandem garage?” is really a question about your vehicle mix. If your second car is a full-size pickup, like a Ford F-150 (around 20 feet), you’re looking at a length closer to 26 or 28 feet to fit it behind a sedan comfortably. I always advise clients to plan for their biggest potential vehicle, not just what they own today.

The Absolute Minimum Tandem Garage Size

You might see builders offer a minimum tandem garage size of 10 feet wide by 20 feet long to save on costs. Technically, you can fit two small cars in there. From a budgeting standpoint, the build two car garage cost matters as you plan. We’ll break down typical ranges and what affects them in the next steps.

I tell clients that a 10×20 tandem is like parking in a closet, it works until you actually need to use the space. Here’s what you give up with the bare minimum:

• You will not have space for any shelves, cabinets, or a workbench along the walls.
• Opening car doors becomes a careful, strategic maneuver to avoid dings.
• There is zero clearance in front of or behind the cars, making it nearly impossible to walk around or perform basic maintenance.
• Getting the rear car out always means moving the front car first.

In my shop, we use these minimums only as a last resort for very tight lots, and we always make sure the homeowner understands the severe trade-off in daily usability.

How Big Is a Double Garage? From Standard to Spacious

When clients ask me how big a standard double garage is, I give them the industry baseline: 20 feet wide by 20 feet deep. That’s the classic, no-frills box you’ll see on many house plans. In terms of garage space square footage, a 20-by-20 footprint comes to about 400 square feet, a handy figure for planning parking and storage.

That 20×20 size gives you two 9-foot-wide parking bays, but once you account for the wall framing and the space needed to open car doors, it feels tight. You can fit two sedans, but you’ll be doing the side-step shuffle to get between them.

The question “how large is a double garage” needs a modern answer. Today’s full-size trucks and SUVs, like a Ford F-150 or a Chevy Suburban, are over 80 inches wide (nearly 7 feet) without mirrors. Park two of those in a 20-foot width, and you have less than a foot of total clearance. You’ll be holding your breath every time you pull in. That’s where two-truck garage dimensions come into play. Knowing the right width and depth helps you park with room to spare.

Why You Should Build Bigger Than the Minimum Double

So, how big should a double garage be? From my shop experience, always go bigger than the minimum. The bare minimum I would ever recommend is 22 feet wide by 22 feet deep. But that’s still just getting by—especially when compared to dimensions for single or double garages with proper ceiling height.

I strongly advise adding 2 to 4 feet in both width and depth. A 24×24 garage is a game-changer. The extra width means you can open your car doors without fear of dinging the other vehicle or the wall. The extra depth lets you walk around the front of a parked car, and it provides that crucial buffer zone for stuff.

Think about your lawnmower, trash bins, or a simple workbench. In a cramped 20×20, these items turn your garage into an obstacle course. I worked on a garage where the homeowner built to the minimum, and his riding mower permanently blocked the front corner of his truck. He regretted it within the first month.

When Rules Get in the Way: Building Codes and Your Plans

One common question I get is, “Do building codes or local regulations affect these dimensions?” Absolutely. You need to think about two separate rulebooks.

Building codes, like the International Residential Code (IRC), set the minimum standards for how a structure must be built for safety. They might specify wall framing requirements or foundation depth, but they rarely say your garage addition must be exactly 20×20.

Your local zoning ordinances are what will limit how big you can build. These rules control your property’s setbacks (how far the building must be from lot lines), maximum coverage, and height. Your dream 30×30 garage might not be allowed if it takes up too much of your backyard.

Always call your local building department first. I had a client who spent money on detailed plans for a massive 28-foot deep garage, only to find his rear setback limit made it impossible. He had to redraw everything, which cost him time and a few hundred dollars extra.

Don’t Forget About Door Sizes and Ceiling Height

Your garage door width is tied directly to your overall dimensions. For a double garage, a 16-foot wide door is the standard. But just like the garage itself, I recommend going wider if you can. Knowing standard garage door width dimensions helps you plan space and choose the right size. This makes it easier to compare options when updating or building.

A wider door, like 18 feet, gives you more wiggle room when driving in and makes navigating around modern mirrors much less stressful. I install a lot of Clopay and LiftMaster doors, and the clients who opt for the wider 18-foot model never complain about having too much space to enter.

Ceiling height is another critical factor. The minimum is often 8 feet. If you ever think you might want a storage loft, a car lift, or just to park a van, plan for more. I recommend a 10-foot ceiling as a great upgrade. For a lift, you’ll need at least 12 feet. That extra vertical space completely changes how you can use your garage.

Making It Work: Planning, Maintenance, and Limitations

Now that you know the standard numbers, the real work begins. This section is about applying those dimensions to your specific life, car, and stuff. Good planning turns a box for cars into a functional, safe space that works for you every day. Let’s walk through the practical steps.

Ease of Planning & Time Investment

This isn’t about swinging a hammer. It’s about using your head before you spend a dime.

Ease of Installation Rating: 2/10. The physical build is for professionals, but the planning is your critical job.

Time Estimate: Plan for 2 to 4 hours of active work. You’ll be researching, measuring your vehicles, and sketching layouts. There’s no drying or waiting time; it’s pure planning.

Start with a 100-foot tape measure (I like the Stanley PowerLock) and graph paper. Measure your vehicles from bumper to bumper and side mirror to side mirror. Don’t guess. Then, mark your proposed garage’s interior walls on the ground with spray paint or a garden hose. Walk the space. Can you open all the doors? Does it feel right? This hands-on test is invaluable. These measurements feed your garage design planning drawings, turning field notes into a practical floor plan. They help map door clearances, vehicle space, and storage layout before you draw up the final plan.

Your Garage Layout Maintenance Routine

A well-sized garage can become unusable fast if you don’t maintain the layout. I treat my garage like a workshop that needs a regular safety check.

I recommend a simple semi-annual “walk-through.” Here’s what I do every spring and fall:

• Check door swing zones. Move any bikes, trash cans, or storage bins that have crept into the arc of your car doors.
• Ensure your main walking path is clear. Items along the walls should not narrow the usable walkway to less than 3 feet. You need room to carry things safely.
• Scan the floor for oil drips, coolant, or loose gravel. A slick spot in a tight parking maneuver is a great way to dent a fender or worse.

This routine takes 15 minutes and prevents 95% of garage headaches. It forces you to respect the dimensions you worked so hard to get.

When Not to Try This (The Limitations)

Knowing when to walk away from a standard plan saves money and frustration. Here are the big red flags I’ve learned to spot.

Do not force a standard 20′ x 20′ double garage onto a very narrow lot. Local setback rules (the required distance from your property line) might make it physically impossible. You’ll waste time and architect fees.

If your daily drivers are a full-size pickup like a Ford F-150 and a large SUV like a Chevy Suburban, a minimum 12′ x 22′ tandem garage will be a daily battle. You’ll be doing the “garage shuffle,” moving one vehicle just to get the other out. It’s not a functional solution.

When your local building department’s code clearly prohibits your desired size, revise your plan. Fighting City Hall on zoning or floor-area-ratio rules is a losing game for a homeowner. A good builder will know these limits and help you design what is actually possible.

Final Pro Tip: Add a Buffer Zone

This is my single best piece of advice, learned from squeezing one too many workbenches into tight spaces.

Take the final dimension you think you need, then add 18 inches of buffer. That extra foot and a half is not for your car; it’s for everything else. It’s the space for a set of Gladiator wall cabinets, the width of your rolling tool chest, and the peace of mind that you won’t ding your door on the wall.

For example, a standard midsize SUV is about 6.5 feet wide. Parking it in a 20-foot wide double garage (two 9-foot doors with a post in the middle) leaves you about 1.25 feet of space on each side. Add my 18-inch buffer to the *total* width, and you see why I built my own double garage at 22′ x 24′. I have space for a workbench and all my tools on one side, and I’ve never once regretted the extra cost for that breathing room. It accommodates the vehicles *and* the life that happens around them.

Garage Dimensions: Your Expert FAQ

I already have a standard-sized garage. How can I make the most of the space?

First, conduct a clearance audit. With the cars parked, measure the actual walking space between vehicles and walls. Any path less than 2.5 feet wide is a hazard and needs addressing. Immediately relocate wall-mounted storage or shelving that infringes on this zone to prevent door dings and improve safety.

Why is my double garage door frame always getting scraped, even in a “standard” 20×20 space?

This is a classic sign of inadequate side clearance. Modern vehicles with wide mirrors often exceed 7 feet. In a tight 20-foot width, you have less than a foot of total wiggle room. My pro tip: install removable foam pool noodles on the door frame as a temporary buffer while you practice your approach, and seriously consider widening the door to 18 feet at the next replacement.

What’s the best storage strategy for a tandem versus a double garage layout?

For tandem garages, prioritize vertical, shallow-depth storage on the long side walls to preserve critical walking lanes. For double garages, utilize the rear wall fully. In both cases, I recommend installing a modular wall track system (like Gladiator GearWall) over fixed shelving. It allows you to reconfigure storage as your needs change without losing floor space.

How do I future-proof my garage dimensions if I might get a larger vehicle later?

Plan for the largest *potential* vehicle, not your current one. If a full-size truck or SUV is in your future, add at least 2 feet to both the width and depth of any “standard” plan you’re considering. This upfront investment is far cheaper than the cost and frustration of a cramped, non-functional garage for the next 20 years. Always build in that buffer.

Final Advice on Garage Dimensions

Before you build or buy, get out your tape measure. Nothing replaces physically verifying your space and the size of the vehicles and items you need to store. My years of experience have taught me that a plan on paper always meets reality in the driveway. Remember these key points for a functional garage:

• Always measure your largest vehicle first, with doors open.
• Use a quality 25-foot tape measure, like a Stanley PowerLock, for accuracy.
• Plan for more than just parking; account for storage, workbenches, and walkways.
• When in doubt, consult your local building department for code requirements.