How many litres of beans does a beanbag need?

It depends on the size. Estimate the cover's internal volume, then fill to about 60 to 80 percent of that so it stays soft but supportive. A large adult beanbag often takes 250 to 400 litres.

What filling do beanbags use?

Most use expanded polystyrene (EPS) beads, sold by the litre. Buy a little extra so you can top up as the beads compress over time.

Should I fill a beanbag completely?

No. Filling to around two thirds keeps it mouldable and comfortable. A fully packed beanbag is firm and less comfortable, and overfilling stresses the seams.

Bean Bag Filling Calculator

This bean bag filling calculator estimates how many litres of polystyrene beads you need to fill or refill a beanbag, so you can order the right amount instead of guessing and ending up with a flat, half-empty seat. Beanbag beads are sold by the litre in bags of around 100 litres, and the quantity a cover needs depends on both its size and how firm you like it. Enter the rough width, depth and height of the beanbag in centimetres and choose a firmness, and the calculator estimates the cover's internal volume by treating the rounded shape as an ellipsoid within those dimensions, then fills it to the fraction you picked. A softer fill uses less and stays mouldable and sink-into comfortable, while a firmer fill uses more and gives more support but less give. The tool then rounds up to whole 100 litre bags so you know how many to buy, and it is worth ordering a little spare because the beads slowly compress with use and most beanbags need a top up after a year or two. Measure the empty cover at its widest points, remember that overfilling stresses the seams, and treat the litres as a close estimate rather than an exact figure.

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Width

Depth

Height

Firmness

258 L

bead filling to buy

Cover volume369 L

Firmness70%

Bags of 100 L3

A beanbag about 80 by 80 by 110 cm holds roughly 369 L inside. Filling it to 70% firmness needs about 258 L of beads, or 3 bags of 100 L.

Estimate only, based on an ellipsoid shape within your dimensions. Beads compress over time, so order a little spare for topping up. Measure the empty cover at its widest points.

How it works

A beanbag is a rounded shape rather than a box, so the calculator estimates the cover's internal volume as an ellipsoid that fits within your width, depth and height: that is pi divided by 6, times the three dimensions, which comes to about 52 percent of the bounding box. Dividing by 1,000 turns cubic centimetres into litres. The filling is that cover volume multiplied by the firmness fraction you chose, since you do not pack a beanbag solid. Finally the litres are rounded up to whole 100 litre bags, the size beads are usually sold in.

Worked example

A beanbag measures about 80 cm wide, 80 cm deep and 110 cm tall. The ellipsoid volume is pi divided by 6, times 80 times 80 times 110, which is about 368,600 cubic centimetres, or 369 litres inside the cover. Filling to a medium 70 percent firmness needs 369 times 0.70, about 258 litres of beads. Rounding up to whole 100 litre bags, that is 3 bags. Choose a firm 80 percent fill instead and you would want about 295 litres, still 3 bags but with less to spare.

Related calculators

Ellipsoid Volume Calculator: volume of an ellipsoid.
Volume Calculator: volume of common solids.
Cylinder Volume Calculator: round container volume.
Sphere Volume Calculator: volume of a sphere.
Tank Volume Calculator: tank capacity in litres.

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