How to Measure for a Loft Ladder (UK 2026)

By the Loft Rung editorial team · Updated 2026 · How we test & score

Measuring wrongly is the single most common and most expensive loft ladder mistake. Two measurements do most of the work, and there's a third check people forget. Here's how to get all three right.

1. The hatch aperture

Measure the CLEAR INTERNAL opening - the actual hole you climb through - not the outer trim or architrave, which can be several centimetres wider. Measure both width and length, and measure in more than one place, as older openings are often not perfectly square. For timber folding ladders this figure is decisive, because those units are supplied sized to specific apertures and cannot be adjusted.

2. Floor-to-ceiling height

Measure from the finished floor directly below the hatch up to the underside of the loft opening. Manufacturers state a ceiling height range for each model, and your measurement must sit within it - not merely near it. Too short is unsafe; too long means the ladder won't sit at the correct climbing angle. Older properties vary a lot, so never assume a standard height.

3. The clear run inside the loft

This is the one people forget. A 2 or 3-section sliding ladder folds up into the loft, so it needs a clear run above and beyond the opening for the stowed sections. Get into the loft and check for water tanks, low trusses, pipework, cabling and stored items in that space. If the run isn't there, choose a concertina ladder, which folds into a far more compact stack, or a telescopic ladder that isn't stowed in the loft at all.

Our top picks

Frequently asked questions

How do I measure my loft hatch for a ladder?

Measure the clear internal aperture - the actual opening you climb through, not the outer trim, which can be noticeably wider. Take width and length, and measure at more than one point since older openings are often out of square. Then measure floor-to-ceiling height to the underside of the opening. For timber folding ladders the aperture must match a stated size exactly.

What if my loft hatch is too small for a ladder?

You have two options. Choose a ladder suited to small openings - a concertina folds into the most compact stack, and a telescopic ladder isn't fitted in the hatch at all. Or enlarge the hatch, which is a structural job involving cutting and trimming a ceiling joist and forming a supported frame, and should be done by a joiner or builder rather than tackled casually.

Bottom line

Our top pick is the Optistep Wooden Timber Folding (our score 9.6/10) - A practical loft ladder (timber folding) for safer loft access..

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