How Big Is a 3 Car Garage? What to Know Before You Build

If you're dreaming of building a home on your land, chances are you've pictured a garage that does more than just park your cars. Maybe it’s a space to store tools, shelter your ATVs or RV, or finally have the workshop you’ve always wanted. That’s where a 3 car garage becomes more than a want - it becomes a practical must-have.

Whether you need extra storage, a place to tinker, or simply room for your growing family’s vehicles, a three car garage gives you the freedom and flexibility to make your garage work as hard as your home does.

At Turner & Son Homes, we specialize in building custom homes on client-owned land across Central Oklahoma. We hear the same question again and again: "How big is a 3 car garage? And how do I make sure I get it right?" If you're wondering the same, you’re in the right place.

Let’s break it down.

How To Calculate 3 Car Garage Square Footage

The simplest way to calculate square footage for a garage, or any space, is to multiply the width by the depth: Width x Depth = Square Footage.

So, if your garage is 24 feet deep and 30 feet wide, your 24x30 garage layout is: 24 x 30 = 720 square feet.

The average square footage of a garage ranges between 240 - 1,000 square feet, depending on the number of cars and extra space you'd like to have.

But here's where it gets tricky: what works for one family may not work for another. A bare-minimum garage might technically fit three cars, but it won’t leave much room to walk between them, store bikes or lawn tools, or open your car doors comfortably.

We often recommend starting with 864 square feet (36x24) as a base if you want space that actually feels usable. If you're storing a larger SUV or truck, you'll want to increase both the width and depth.

Also factor in framing, interior wall space, and mechanical clearances—those will eat up square footage you can’t use.

Planning Tip: Consider how you’ll use the space. Do you need room for a workbench? Freezers? Shelves? Planning this before you build can save money, and headaches, later.

Tools You Need to Measure Your 3 Car Garage

Even if you're not doing the physical build yourself, being able to measure and visualize your 3 car garage is critical for making informed decisions.

Here’s what you’ll need:

● Tape Measure or Laser Measurer – for accurate distance measuring
● Graph Paper or Floor Planning Software – to sketch layout ideas
● Spray Paint, Landscape Flags, or Marking Chalk – to outline on your land
● Notebook or Digital Planner – to log what you want in the garage (e.g., “8-ft shelf for tools”
or “extra space for lawnmower”)

If you’re working with Turner & Son, we’ll also do a site walk on your Oklahoma land. That means we help you figure out garage (and home) placement, how the driveway connects, what angles work best, and how to prevent drainage issues or tight squeeze points.

Pro Insight: It's easy to underestimate how much space your garage needs until it’s too late. When in doubt, oversize by a few feet - you'll never regret the extra space.

What is the Standard Size of a 3 Car Garage?

The term "standard" can be misleading - because there’s no true one-size-fits-all, especially in custom homes. But generally, most 3 car garages fall within these dimensions:

A 3 car garage needs to be at least 30 feet wide to fit three cars side-by-side. But if you want to avoid door dings and tight walkways, plan closer to 36–40 feet wide.

Depth is just as important. For small cars, 20 feet is fine. But for SUVs, full-sized trucks, or storage at the front of the garage, we recommend 24–30 feet.

Also consider overhead door height.. A 7-foot tall door may work for cars, but for many trucks and SUVs, you’ll want an 8-foot door.

If you are considering an 8-foot door, you may consider increasing the ceiling height from 9 feet to somewhere between 10-12 feet.

What's The Average Size of a 3 car garage?

So, you might be asking “what’s typical?” Based on our experience and industry trends, the average size of a three car garage is around 864 square feet, typically measured as 36 ft wide by 24 ft deep.

But again, the “average” may not work for you.

Some clients go with a larger 40x30 layout to allow for hobbies like woodworking or auto repair. Others opt for an L-shape or tandem-style garage to fit a narrow lot.

Use your lifestyle as a guide:

● Do you need space for sports gear, bikes, or yard equipment?
● Will you be parking larger vehicles like a truck or full-sized SUV?
● Do you want this to double as a gym, hobby space, or man cave?

You don’t have to build a massive garage. You just have to build smart.

Factors to Consider When Building a 3 Car Garage

Here are the five biggest factors to think about as you design your garage:

1. Lot Shape and Setbacks

Depending on how your lot is shaped and where you can legally place structures, your garage may need to shift sideways, forward, or back. Our team helps assess setbacks and local code requirements to make sure your garage fits the land and the law.

2. Garage Door Style

You can go with three single doors, a double + single, or one oversized door. Each has pros and cons related to curb appeal, cost, and functionality.

3. Access Points

Do you want the garage attached to the house? Or detached with a breezeway? Would a side-load layout make your home more efficient? These access decisions affect your home’s flow.

4. Utilities and Lighting

Don’t overlook this: Will you need outlets for tools or a fridge? Will natural light come in, or do you want windows? Want to add HVAC later? Pre-planning these features ensures comfort and saves future cost.

5. Budget

Wondering how much is a 3 car garage? Expect costs to start around $30,000 and go up based on materials, roof type, finishes, and extras like insulation or HVAC. Turner & Son’s fixed-price guarantee ensures your garage cost won’t change after you sign your contract.

Common 3 car garage layouts: What's Best For You?

Here are the most popular 3 car garage configurations we build:

● Straight Triple Bay – Three stalls side-by-side. Simple, functional, and classic.
● 2+1 Layout – Two stalls in front, one offset or tandem behind. Ideal for narrow or deep lots.
● L-Shaped Garage – Great for maximizing corner lots or separating shop space from parking.
● Detached Garage with Breezeway – Adds character and charm, especially on rural land where space isn’t limited.

Your layout doesn’t have to match what’s “standard.” Let your lot and your lifestyle drive the design.

Frequently Asked Questions about 3 Car Garages

How many square feet is a 3 car garage?

A 3 car garage typically ranges from 700 to 1,200 square feet, depending on layout, storage, and features. The most common size is around 864 square feet (roughly 36×24 feet).

How big is a 3 car garage in feet?

Most 3 car garages measure 30 to 40 feet wide and 20 to 24 feet deep, with ceiling heights between 7 and 12 feet. A standard layout is about 36×24 feet.

How Much does a 3 car garage cost?

In Oklahoma, building a 3 car garage usually costs $30,000 to $70,000 or more, depending on materials, finishes, and whether you add upgrades like insulation, storage, or living space above.

What is the minimum size for a 3 car garage?

The smallest recommended size is 30×20 feet (600 sq ft). While you can technically fit three cars, maneuverability and storage will be very limited at that size.

Can I build a 3 car garage on a narrow lot?

Yes, you can build a 3 car garage on a narrow or irregular lot. Tandem layouts (one car parked behind another) or offset bays are common solutions to maximize space.

At Turner & Son Homes, we’re not just builders - we’re problem solvers. When it comes to garages, we help our clients think through what they’ll need not just today, but five or ten years from now.

We know your garage isn’t just for cars. It’s for your gear, your projects, and your peace of mind.

If you’re planning to build a custom home, and want a 3 car garage that fits your life instead of forcing you to fit into someone else's mold, you have found the right “Anti-Builder” builder.

You deserve a garage that fits your cars and your lifestyle. Let’s talk through the smart way to design it.