How the fit calculator works

The short version: we model the boot and its opening as rectangles, test every permitted orientation of your item against both, add a buffer you choose, and tell you what we couldn’t check. A “likely fits” result is never a guarantee.

1. Where vehicle measurements come from

Each vehicle record stores individual measurements (in millimetres), and each measurement carries its source, page or table reference, the source’s own description of what was measured, and an evidence tier: manufacturer (published technical data or brochures), independent (physical measurement by a credible third party) or user-verified (submitted measurements we have reviewed — none published yet). We retrieve every document ourselves; we don’t copy third-party databases or use forum figures. See all sources.

We never estimate a missing dimension from the boot volume or vehicle class, never copy figures between generations, and record when a figure is taken from a closely related variant. Missing values stay missing — the calculator then asks you to measure them.

Coverage labels

• Detailed measurements available — floor length, narrowest width, usable height, opening width and opening height are all sourced.
• Partial measurements — at least one of those is missing.
• Cargo volume only — only litres are known; not usable for fit (we don’t list these).
• Manual measurements required — no usable data; use your own measurements.

2. Why boot volume isn’t enough

Volume figures (litres, cubic feet) describe how many standard blocks or a measured volume fit — they don’t tell you whether a long or rigid object can be placed or passed through the opening. Two boots with the same volume can have very different lengths and openings. Volume is shown on vehicle pages for reference only and is never used in calculations. Read more.

3. The geometric model

The cargo space is a rectangular box: length along the car (seatback to tailgate), width across the car at its narrowest point (normally between the wheel arches), and height to the first restriction. The opening is a rectangle of clear width × height.

Orientations

A rectangular item L × W × H can sit in up to six axis-aligned orientations. We test each unique one (duplicates are skipped when dimensions are equal). “Must stay upright” keeps the stated height vertical; “Must lie flat” keeps the smallest dimension vertical. Prohibited orientations are never used to produce a positive result.

Interior and opening are separate checks

For each orientation we check (a) whether it fits inside the cargo box and (b) whether it can pass straight through the opening. In the straight-through test the item moves along the car’s length, so the face that must pass the opening is its across × vertical cross-section — not its length.

4. Clearance allowance

You choose a buffer — none, 2 cm, 5 cm or a custom value — which is added to every item dimension on every axis checked. It is a safety margin you select, not a scientific tolerance, and it never changes the published vehicle figures. Independently of your choice, if the best orientation leaves less than 1 cm of raw space on any axis, we show “Might fit” because measurement precision, seals and trim can easily absorb that.

5. Result classification

Transport notes are shown separately: weight above a documented load limit, packages of 25 kg or more (consider a second person), upright/flat restrictions, fragile items, folded seats removing passenger places, and tall items that may block the rear view.

6. Angled placements and manoeuvres (exploratory)

When no straight orientation fits, we test in-plane rotations (0.25° steps) on the floor and in the vertical plane, and diagonal passage of the cross-section through the opening, using exact projected dimensions. These results are always labelled exploratory: a diagonal fit in a rectangle doesn’t prove the item can be manoeuvred into place past wheel arches, seatbacks or hinges.

7. Seats up vs folded

Each configuration uses its own measurements. If a source gives a seats-folded length but no seats-folded width or height, we use the seats-up width/height (they rarely change) but label this and never show “Likely fits” on that basis. Folded seats are often not flat — measure the step or slope if your item is long and rigid.

8. Multiple packages and multiple items

Each package of a multi-box product is checked separately; the product only counts as fitting when every package does. To see whether everything fits together, we use an extreme-point, first-fit packing heuristic with several item orderings: items are placed at the lowest, deepest free position, in an orientation that fits and passes the opening; stacked items need at least 60% support; fragile and “nothing on top” items support nothing. It is a heuristic — it doesn’t explore every arrangement, so “not placed” means “not found”, and a found arrangement isn’t proof it can be loaded that way.

9. Units and precision

Everything is calculated in millimetres. Inputs in cm, m, inches or feet-and-inches are converted once, without rounding, and results are rounded only for display. A 0.5 mm tolerance absorbs unit-conversion rounding.

10. Testing

The fit engine, packing heuristic, unit conversion, share links, saved-data import and data validation are covered by automated tests, including the cases described above (opening as the limiting factor, missing opening data, clearance at exact matches, upright restrictions, multi-package failures and cm/inch consistency).

Limitations

• Real boots aren’t rectangles: curved panels, sloping seatbacks, hinges, trim and tapered openings can block an item that passes the model.
• Manufacturer figures are measured at specific points, often for a particular trim; your car may differ.
• Packaging can be larger than listed, and soft items behave differently from rigid boxes.
• The model doesn’t know about legal or safe-loading requirements in your country. See securing cargo safely.