Will it fit in my car?
Two separate questions: does it get through the tailgate or side door, and does it then fit inside? Carry Clearance checks both as steps on a route.
Step 1: the opening
Add a "doorway or opening" step with the clear width and height of the tailgate or door opening. Measure the narrowest point, which is often at the top corners or the latch.
Step 2: the cargo space
Add a "space" step with the length, width and height you can really use: past wheel arches, with the seats folded the way you'll fold them. The item may lie at an angle on the floor. Going diagonally across the floor is checked exactly. Propping it diagonally in 3D isn't credited.
What isn't checked
- Getting from the opening into the final position (swinging it round inside).
- Sloping seat backs, bumps and the load floor's lip.
- Load limits and securing the load. Follow your vehicle manual's payload and cargo instructions, never block your view, and tie loads down. Many places have laws on unsecured or projecting loads.
Not professional advice. This guide explains geometry. It cannot see your building or your item. Lifting and carrying heavy furniture can injure people and damage property, so use professional movers when in doubt.