Measuring for a bench cushion is one of those jobs that seems straightforward until you’re kneeling on wet paving with a tape measure that keeps snapping back. A cushion that’s too small slides about; one that’s too big bulges over the edges and wears quickly. The good news is that a few careful measurements—and a sketch—will get you a snug fit, even if your bench is curved, corner-shaped or built around a tree.

Start with the seat, not the frame

Before you measure anything, clear the bench. Remove old cushions, sweep off leaves and grit, and check that the seat is sound. You’re measuring the surface the cushion will sit on, not the outer frame or the legs. If the bench has a slatted seat, measure across the slats at the point where the cushion will rest. If there’s a lip or a raised edge at the front, decide whether the cushion should sit inside it or overhang. For most garden benches, the cushion sits between the arms and against the backrest, so those are your boundaries.

Measuring length and width

Length is the measurement from one end of the seat to the other, usually left to right as you face the bench. Width is the measurement from the front edge to the backrest—what many people call depth. It’s easy to mix the two up, so label your sketch clearly. Use a metal tape measure for straight runs; it won’t stretch like a fabric tape. Measure at three points: the front edge, the middle and the back edge. Benches can be slightly out of square, especially wooden ones that have weathered. Write down the smallest and largest figures. If they differ by more than a centimetre or two, you’ll need to decide whether to average them or ask for a cushion shaped to the larger size with a little compression.

Benches with arms

If your bench has arms, measure the clear space between them. That’s the maximum width your cushion can be. Also measure from the front of the seat to the backrest. If the arms slope inwards, measure the gap at seat level, not at the top of the arms. For a cushion that tucks under the arms, you may need to reduce the width by a centimetre so it slides in without catching.

Tapered and curved seats

Some benches are wider at the front than the back. Measure the front width and the back width separately, and note the difference. A tapered cushion will fit better than a rectangular one. For curved seats, measure the straight-line distance across the front (the chord), then the depth at the centre and at each end. A flexible tape measure is useful here, but don’t rely on it alone—see the template method below.

Getting depth right

Depth is the distance from the front edge of the seat to the backrest. If the backrest is upright, measure from the front edge to where the backrest meets the seat. If it’s angled, measure at seat level, not along the slope. The cushion needs to fill that space without pushing the backrest away from the frame. If you’re ordering a thick cushion, remember that foam compresses slightly, but the cover doesn’t stretch. A cushion that’s two centimetres too deep will buckle or lift at the front. Measure twice, and if you’re between sizes, go for the slightly smaller depth—it will still look neat and won’t fight the backrest.

Odd-shaped benches: corners, curves and cut-outs

Corner benches, L-shaped seats, hexagonal arbours and benches built around tree trunks all need a different approach. Don’t try to reduce them to a rectangle. Instead, break the shape down into sections. For an L-shaped bench, treat each leg as a separate rectangle and measure the corner join carefully. For a hexagonal bench, measure each side and the distance across the centre. For a bench with a cut-out for a post or trunk, measure the cut-out’s width and depth, and its position from the nearest corner.

Making a template

For any shape that isn’t a simple rectangle, a paper or cardboard template is the most reliable method. Here’s how:

1. Lay a large sheet of paper, wallpaper lining or thin cardboard over the seat.
2. Press it into the corners and along the backrest. If the bench has slats, use tape to hold the template in place.
3. Trace the outline of the seat area with a pencil, following the arms, backrest and any cut-outs.
4. Mark the front edge clearly, and write “front” on the template.
5. Cut the template out, then test it on the bench. Adjust with scissors until it sits flat without gaps or overlaps.
6. Fold the template if you need to post it, or take a photo with a ruler beside it for scale.

A template also lets you mark where ties should go, which brings us to the next step.

Tie positions and fixings

Cushion ties are usually attached to the backrest, the arms or the seat frame. Measure from the left edge to the first tie, then the distance between each tie. If your bench has existing ties, measure from the same reference points on the bench. For a bench without ties, decide where you want them: most people put one at each corner and one in the middle of a long cushion. Measure the height of the tie from the seat surface if it wraps around a backrest rail. Also note whether you need velcro, press studs or a non-slip underlay. If you’re replacing a cushion, measure the old ties before you throw it away—that’s the easiest guide.

Double-checking before you order

Before you send your measurements, lay them out on a sketch. Include:

• Length at front, middle and back.
• Width from front edge to backrest.
• Depth at each end and in the centre.
• Corner shape (square, rounded, chamfered).
• Tie positions and type of fixing.
• Cushion thickness you want.

Measure once more, ideally in the morning when the bench is dry and the tape isn’t kinked. If your bench is very irregular, ask the cushion maker whether they want a template or a photo with dimensions. A snug cushion is worth the extra ten minutes. It stays put, protects the seat and makes the bench feel like a proper piece of furniture. And if you’re unsure about anything structural—loose joints, rot or a wobbly frame—get the bench checked by a carpenter before you cover it up.

Photo: Pexels / Pixabay