Will it fit? · Use case

Through the door,
or back to the store?

Enter the dimensions of your appliance or furniture. The calculator gives you the space diagonal — the longest straight line inside the box — which is what you compare against your doorway to know if it fits.

How to use the diagonal

The fit decision.

For an appliance to clear a doorway, you can move it straight through if the opening is bigger than the appliance's smallest face. When it's close, you can tilt the appliance — and that's when the diagonal matters.

Specifically, the relevant number is the face diagonal of the smallest two dimensions. If the diagonal of (width × depth) is less than the doorway's diagonal, you can angle it through.

Example: 36" wide × 30" deep × 70" tall fridge
Smallest face: 36" × 30"
Face diagonal: √(36² + 30²) = 46.9"

Standard 32" doorway diagonal: ≈ 86"
Fits if tilted.
Don't forget

Real-world adjustments.

  • Subtract 1–2" from your doorway measurement for trim and door hardware
  • Subtract 2" from appliance dimensions if it's still in its box and you're keeping the box on
  • Hallway turns are often tighter than doorways — measure the narrowest point along the route
  • Remove the door if you can — that buys you 1–3" of clearance
  • For fridges: always remove the doors and handles before moving — this is in your owner's manual
Reference clearances

Standard doorway sizes.

Doorway type Typical W × H Diagonal
Interior bedroom door30" × 80"~85.4"
Standard interior door32" × 80"~86.2"
Wider interior door36" × 80"~87.7"
Standard exterior door36" × 80"~87.7"
Sliding glass door60" × 80"~100"
Single garage door96" × 84"~127"
Always measure your actual doorway — these are typical sizes, not yours.
Fit FAQ

Common questions.

How do I check if a fridge fits through a doorway?
Measure the doorway's width and height, and the fridge's three dimensions. The fridge fits if its smallest face (width × depth) is less than the doorway opening. If the smallest face is slightly larger than the doorway, tilting may work — the diagonal of the smallest face must be less than the doorway's diagonal.
What's the space diagonal of a box?
The space diagonal is the longest straight line that fits inside a rectangular box, going corner to opposite corner. It equals √(length² + width² + height²). For appliance fit, the relevant number is usually the face diagonal — the diagonal of the smallest two dimensions, which is what determines tilt clearance.
Can I just take the door off?
Yes, and often you should. Removing an interior door buys you 1–3" of clearance — sometimes the difference between fits-easily and doesn't-fit-at-all. Most interior doors come off in 5 minutes with a hammer and a flathead (tap up the hinge pins from below).
What about stairs and hallway turns?
The doorway isn't usually the hardest part — it's the L-shaped hallway, the narrow stair landing, or the railing on the way up. Measure the narrowest pinch point on the route, not just the destination doorway.
Related reading

From the blog.

Article
Will My Fridge Fit Through the Doorway? →
Article
The Box Diagonal Formula →