Front Door Sizes: Standard Dimensions, How to Measure and When You Need Custom

Front door sizes look simple until you measure your own opening. Most new homes use a 36 inch by 80 inch door, and many older homes do not. This guide gives the standard sizes, the sizes in our own catalogue, a step-by-step way to measure, and a list of what to send us so we can quote your door.

We are EHI Custom Doors. We manufacture and install custom fiberglass front doors and back doors, and we build each one to your measured opening.

Standard Front Door Sizes at a Glance

What Our Catalogue Offers

Our catalogue shows models in oak grain, mahogany grain and smooth finishes. Door heights are 6 foot 8 and 8 foot. Widths run from 28 to 42 inches depending on the model, with 32, 34 and 36 inches the most common, and the widest models at 40 and 42 inches. Sidelights come in 12 and 14 inch widths, and there is a 48 by 108 inch custom-order size for very large openings.

These are starting points. Every door we build is made to your measured opening, so an odd size is not a problem. Browse the door catalogue and photos of doors we have installed to see the range.

When a Standard Size Fits, and When You Need Custom

• Standard fits: newer homes with square, standard-width openings and a normal 80 inch height
• Custom helps: older homes where the opening has moved or was cut to an odd size
• Custom helps: brick or stone openings that cannot be easily changed
• Custom helps: arched tops, curved transoms and very wide or very tall entrances
• Custom helps: tall ceilings where an 80 inch door looks undersized

Our guide on custom doors vs stock doors explains why a made-to-measure door fits better in these cases, and our guide to arched and custom-shaped doors covers curved and oversized openings.

How to Measure Your Front Door Opening

1. Measure the old door slab for reference: width, height and thickness.
2. Measure the width of the opening between the inside edges of the jambs at the top, the middle and the bottom. Use the smallest number.
3. Measure the height from the head jamb to the sill on the left, in the centre and on the right. Use the smallest number.
4. Check for square by measuring the two diagonals corner to corner. If they match within about 1/8 inch, the opening is close to square.
5. If you have sidelights or a transom, measure each one and the overall width.
6. Note the sill or threshold, and the step below it.
7. Note which way the door swings and which side the hinges are on.
8. Take photos from inside and outside, straight on, and close up of the frame and the sill.

Door Handing and Swing

For an exterior door, handing is judged from the outside. If the hinges are on the left as you face the door, it is a left-hand door. If they are on the right, it is right-hand. You also need to say whether the door swings in or out, because the same handing can be ordered either way. Our back door replacement guide compares inswing and outswing doors.

Sidelights, Transoms and Overall Width

Sidelights and a transom change the overall opening. A 36 inch door with two 14 inch sidelights spans about 64 inches of door and glass before the frame. That is close to a 60 inch double door, with one seam and one lock. Our guide to single vs double entry doors compares the two, our guide to sidelights and transoms covers design, and widening an opening is a structural change that needs a building permit in Toronto.

Sizing Mistakes to Avoid

• Measuring the old door and not the opening
• Measuring at one point, when openings are often wider at the top than the bottom
• Ignoring the sill and the step, which decide the door height
• Forgetting the trim and brickmould around the door, which our guide to exterior door trim and brickmould explains
• Ordering a standard size without checking that the opening is square
• Leaving out the swing and the handing

What to Send Us for a Quote

• Photos of the entrance from outside and inside, straight on
• Close-ups of the frame, the sill and any damage
• Rough width and height, and the sidelight and transom sizes if you have them
• Which way the door swings and which side the hinges are on
• Notes on the wall around it, such as brick, stone or siding

Call EHI Custom Doors at 647-952-2311 or request a quote. We are open Monday to Sunday, 9 AM to 5 PM, and there is no pressure to book on the spot. A custom fiberglass single door starts at $2,500 installed and a double door at $5,100, and our guide to custom exterior doors cost in Toronto shows what moves the price. Read what customers say on our reviews page.

Front door sizes are easy once you know which numbers matter: the smallest width, the smallest height, whether the frame is square, and which way the door swings. Send those with photos and we will handle the rest.