Opening the Door to Design: Your Guide to Standard Exterior Door Size

Think about the last time you walked up to a house. Chances are, your eyes went straight to the front door. It’s the handshake of your home – the first impression visitors get, and the detail you’ll pass through dozens of times a day. But before you can pick the perfect color or design, you’ve got to nail one essential detail: the size.

Here’s a fact you might not know: according to Orillia Matters, the average household replaces or upgrades exterior doors about every 20–25 years, and front doors are one of the most common home improvement projects after windows and roofing. On top of that, research from the National Association of Realtors shows that a new front door consistently ranks among the top five remodeling projects for return on investment, recouping 65%–70% of its cost at resale, according to Investopedia.

But before you can pick the perfect color or design, you’ve got to nail one essential detail: the size. Understanding standard exterior door sizes isn’t just a technical step – it can save you money, simplify installation, and make sure your home feels welcoming and well-proportioned.

What Counts as a Standard Exterior Door Size?

Across Canada and North America, the go-to exterior door size is 80 inches tall (6 ft 8 in) and 36 inches wide, with a thickness of 1 ¾ inches. According to Wikipedia, a standard U.S. residential exterior door is typically 36 × 80 inches.

But not every entryway sticks to those exact numbers. Here are other common sizes you’ll find right off the shelf:

• 30 or 32 inches wide – often used for side doors, basement entries, or utility access.
• 34 inches wide – a little less common, but still widely available.

When contractors talk about “door size,” they’re usually referring to the door slab itself (the panel you see and swing open). Behind the scenes, there’s also the rough opening – the hole in the wall where the door and frame fit. That opening is typically 2 to 2 ½ inches wider and taller than the slab, so everything slots in properly.

Why These Measurements Matter for You

You might be wondering: why fuss over a couple of inches? Here’s why it makes a difference:

• Cost savings: Standard sizes are mass-produced, which makes them far more affordable than ordering custom.
  
• Faster turnaround: Walk into almost any home improvement store and you’ll find standard sizes in stock. No waiting weeks for a special order.
  
• Simpler installation: Contractors (and even ambitious DIYers) find standard doors much easier to work with – which can save you on labor costs.
  
• Better planning: Knowing your sizes upfront helps you design your entryway confidently without budget-busting surprises later.
  

Standard vs. Custom Door Sizes

Parameter	Standard Size Doors	Custom Size Doors
Price	Lower	Significantly Higher
Availability	High (In-stock)	Low (Made-to-order)
Delivery Time	Immediate to a few days	Weeks to months
Installation Complexity	Straightforward	More complex, may need structural changes
Design Flexibility	Limited to standard dimensions	Virtually unlimited

How to Choose the Right Door Size
The trick is to measure properly before you buy. Don’t just grab a tape measure and size up the old door – that number only tells you the slab size, not whether a new pre-hung unit will fit your wall opening.

Here’s the right way to do it:

1. Remove the trim: Gently take off the interior casing to expose the studs.
   
2. Measure width: Check the distance between studs at the top, middle, and bottom. Write down all three and go with the smallest.
   
3. Measure height: Measure from the subfloor to the bottom of the header on both sides. Again, use the smaller number.
   
4. Check the rough opening: If it’s roughly 38 inches wide by 82 inches tall, you’re in good shape for a standard 36×80 pre-hung door.

Mistakes Homeowners Often Make

• Measuring only the slab: That won’t tell you if the full door system will fit. Always measure the rough opening.
  
• Assuming all homes are standard: Older houses, in particular, can surprise you with non-standard sizes.
  
• Skipping the level check: If your opening isn’t square or plumb, you may need adjustments to avoid a sticky, uneven swing.
  
• Ordering custom too soon: Sometimes a small tweak to the opening is all it takes to fit a standard door and save thousands.

A Growing Design Conversation

While 36 inches works for most entryways, there’s an increasing push toward wider, more accessible doors. Homeowners planning to “age in place” – or simply make their homes more stroller- and wheelchair-friendly – are opting for openings 38 inches or wider. The Canada Mortgage and Housing Corporation (CMHC) recommends accessible entrances be at least 915 mm (36 inches) wide to comfortably accommodate mobility devices.

It’s a shift toward universal design: homes built not just for today, but for the long run. Though it may cost more upfront, it’s an investment in comfort, accessibility, and future-proofing.

FAQ – Common Door Sizing Questions

1. How do I avoid buying the wrong size door and wasting money?

The #1 mistake homeowners make is measuring only the old slab instead of the full rough opening. Always remove the trim and measure stud-to-stud and floor-to-header. If your opening is close to 38″ × 82″, a standard 36″ × 80″ door will usually fit perfectly – saving you the cost of a custom order.

2. Is a standard 36×80 door always the best choice, or should I think bigger?

For most homes, yes – 36×80 is the industry standard and keeps costs low. But if you’re planning to stay long-term, wider doors (38″+) can make life easier for moving furniture, handling strollers, or future accessibility needs. Many homeowners are now choosing “universal design” widths to future-proof their entryways.

3. Why pay more for a custom door if standard sizes are cheaper and faster?

Custom sizing only makes sense when your home’s structure won’t allow for a standard fit, or when you want a unique design that standard options don’t cover. Otherwise, small adjustments to the opening are often far less expensive than ordering a custom slab – which can cost thousands more and take months to arrive.

Final Thought

Your front door isn’t just an entry point – it’s part of your home’s story. By understanding standard exterior door sizes and measuring carefully, you’ll avoid headaches, save money, and end up with a door that looks great and works perfectly. Whether you stick with tried-and-true dimensions or explore wider, more accessible options, the right choice will welcome guests – and you – home for years to come.