Bean Bag Filling Calculator
How much filling for a bean bag? Enter your bag's shape and size, pick a filling material, and get the exact bean bag refill amount in litres, kilograms and retail bags — plus a top-up mode for a bag that has gone flat.
Pear mode assumes height = 1.3 × diameter (typical pear proportions).
Typical retail range 10–20 kg/m³ (see sources note below).
85% is the standard fullness. 100% is drum-tight; 70% is soft and slouchy.
Your bean bag refill amount
- Bag volume
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- Filling needed
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- Filling weight
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- Bags to buy
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- Estimated cost
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- Top-up needed
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How the bean bag filling calculation works
Every bean bag filler calculator follows the same three steps. First, estimate the geometric volume of the bag. A box bean bag is exact: length × width × height. A round bean bag is treated as a sphere (4/3 × π × r³). A pear-shaped bean bag is approximated as an ellipsoid 1.3 times taller than wide — a documented approximation, because no two pear bags share one exact geometry.
Second, multiply the volume by your target fill percentage. Bean bags are rarely filled to 100%: 85% fill leaves room for the beads to shift when you sit, which is what makes the seat mould around you. Third, convert the fill volume into weight with the material's bulk density, and into retail bags by dividing by the bag size and rounding up.
Worked example 1: 4 ft pear bean bag, EPS beads
A classic adult pear bean bag with a 4 ft (121.92 cm) diameter. Pear height is taken as 1.3 × 121.92 = 158.50 cm. Volume = 4/3 × π × 60.96 × 60.96 × 79.25 = 1,233.58 L (43.56 cu ft). At 85% fill that is 1,048.54 L of beads. EPS beads at 15 kg/m³ weigh 1,048.54 × 15 / 1,000 = 15.73 kg (34.67 lb). Sold in 100 L bags: 1,048.54 / 100 = 10.49 → buy 11 bags.
Worked example 2: 70 × 60 × 50 cm box bean bag
Volume = 70 × 60 × 50 = 210.00 L. At 85% fill: 178.50 L of EPS beads, weighing 2.68 kg. That is 1.79 bags of 100 L → buy 2 bags. At $13 per bag the estimated cost is $26.00. If the bag later goes 30% flat, top-up mode says add 53.55 L (0.80 kg) — one more 100 L bag.
Bean bag size filling chart (diameter 1–10 ft)
Quick reference for round bean bags. Volumes are geometric; the EPS columns use the standard 85% fill.
| Diameter | Volume (sphere) | Volume (pear) | EPS fill @ 85% | EPS weight |
|---|---|---|---|---|
| 1 ft | 14.8 L | 19.3 L | 12.6 L | 0.19 kg |
| 2 ft | 118.6 L | 154.2 L | 100.8 L | 1.51 kg |
| 3 ft | 400.3 L | 520.4 L | 340.3 L | 5.10 kg |
| 4 ft | 948.9 L | 1,233.6 L | 806.6 L | 12.10 kg |
| 5 ft | 1,853.3 L | 2,409.3 L | 1,575.3 L | 23.63 kg |
| 6 ft | 3,202.6 L | 4,163.3 L | 2,722.2 L | 40.83 kg |
| 7 ft | 5,085.5 L | 6,611.2 L | 4,322.7 L | 64.84 kg |
| 8 ft | 7,591.3 L | 9,868.6 L | 6,452.6 L | 96.79 kg |
| 9 ft | 10,808.6 L | 14,051.2 L | 9,187.3 L | 137.81 kg |
| 10 ft | 14,826.7 L | 19,274.7 L | 12,602.7 L | 189.04 kg |
EPS beads vs microbeads vs shredded foam
| Material | Density used | 250 L weighs | Feel |
|---|---|---|---|
| EPS beads | 15 kg/m³ | 3.75 kg | Classic, light, cheapest |
| Microbeads | 20 kg/m³ | 5.00 kg | Moulds to body, compresses faster |
| Shredded foam | 40 kg/m³ | 10.00 kg | Plush, supportive, heavy |
The densities above are verified against independent sources: the EPS figure is the top of three retail listings (12.5, 13.75 and 15.2 kg/m³; mean ≈13.8), consistent with a published measurement of 13–15 kg/m³, and the shredded-foam figure comes from a retail listing of 5 lb expanding to 2 cu ft. See the sources note below and override any value in the calculator if your supplier quotes a different bulk density.
Practical tips
- Always round bags up. A spare half bag is useful for the first top-up, which most EPS bags need after 6–12 months.
- Convert between units freely: 1 cu ft = 28.32 L. The calculator shows both.
- Fight static: wipe the bag opening with an anti-static dryer sheet and pour through a wide funnel.
- Measure a pear bag at its widest point; the 1.3× height assumption handles the rest.
Quick answers
- How much bean bag filling do I need?
- As a rule of thumb, how much filling for bean bag chairs equals 85% of the bag's geometric volume in litres. So how many litres of filling for a bean bag that is a 4 ft pear? About 1,049 L of EPS beads — see worked example 1.
- Giant bean bag how much filling?
- The bean bag chair filling amount for a giant bean bag (8–10 ft round) is 6,452.6–12,602.7 L of EPS at 85% fill. Check the bean bag filling chart and the bean bag size filling table above for every size in between.
- Is this also a bean bag top up calculator?
- Yes. This bean bag refill calculator includes a top-up mode: enter how flat the bag has gone and it tells you the extra litres to buy.
- How much EPS filling for bean bag projects?
- Use the EPS beads calculator settings above: fill litres × 15 kg/m³ ÷ 1,000 gives the weight, and dividing by your retail bag size gives the bag count.
- Microbeads vs EPS beads bean bag — which to pick?
- Microbeads mould around the body better; EPS beads are lighter, cheaper and the classic choice.
- What is the shredded foam bean bag filling weight?
- About 2.7× EPS: 250 L of shredded foam weighs 10.00 kg versus 3.75 kg of EPS beads.
- Bean bag fill percentage — how full should a bean bag be?
- 85% is standard. Firm enough to support you, soft enough to sink into — most people land at 80–90%.
- Bean bag filling density and weight
- How much does bean bag filling weigh? Multiply litres × density ÷ 1,000. Densities: EPS 15, microbeads 20, shredded foam 40 kg/m³.
- Unit conversions
- The litres to kg bean bag filling conversion and the cubic feet to litres bean bag conversion (1 cu ft = 28.32 L) are shown live in the results.
- How often top up bean bag?
- Every 6–12 months for a daily-used EPS bag; top-up mode computes the exact litres.
- Pear shaped bean bag volume
- Calculated as an ellipsoid 1.3× taller than wide — a documented approximation explained above.
- 4ft bean bag filling litres
- 1,048.54 L of EPS at 85% fill, weighing 15.73 kg — 11 bags of 100 L.
Density sources: retail listings (Carousell SG, Shopee SG, Amazon Posh Creations, Welacer) and MDPI Materials 2019; conversions per NIST. Full citations in SOURCES.md in the tool folder.
Frequently asked questions
How much filling does a bean bag need?
Multiply the bag's volume by your target fill percentage, then convert to litres. For a box shape that is length x width x height; for a round bag it is the sphere volume 4/3 x pi x r^3; for a pear shape this calculator uses a documented ellipsoid approximation (height = 1.3 x diameter). A 4 ft pear bean bag holds about 1,233.58 L of air space, needs about 1,048.54 L of EPS beads at 85% fill, and that fill weighs about 15.73 kg.
What is the standard fill percentage for a bean bag?
85% is the industry-standard starting point and the default in this bean bag filler calculator. 100% gives a very firm, drum-tight seat that is hard to sink into; 70-75% gives a soft, slouchy lounge feel. Most people settle between 80% and 90%. Use the fill slider above to see how the bean bag refill amount changes.
EPS beads vs microbeads vs shredded foam: which filling is best?
EPS beads are the classic choice: light (about 15 kg per cubic metre), cheap, and widely sold in 100 L bags. Microbeads are smaller EPS beads that mould around the body better but pack denser (about 20 kg/m^3) and compress a little faster. Shredded foam feels plush and supportive but is far heavier (about 40 kg/m^3), so the same volume can weigh nearly three times as much. Pick the material in the calculator to compare weights side by side.
What density values does this calculator use?
EPS beads: 15 kg/m^3, the top of three independent retail data points (12.5, 13.75 and 15.2 kg/m^3; mean ≈13.8), consistent with a published measurement of 13-15 kg/m^3. Microbeads: 20 kg/m^3 (estimate: smaller beads pack tighter). Shredded foam: 40 kg/m^3, measured from a retail listing of 5 lb expanding to 2 cu ft (2.268 kg / 0.0566 m^3 = 40.05 kg/m^3). Full citations are in the sources section, and you can override any density in the settings box.
How often should I top up my bean bag?
EPS beads slowly compress under body weight, so most bean bags go a little flat after 6-12 months of daily use. If your bag has lost about 30% of its loft, switch on top-up mode above and enter 30: the calculator tells you exactly how many extra litres to buy instead of guessing. Buying one spare 100 L bag with your first order covers most future top-ups.
How do I measure a pear-shaped bean bag?
Lay it on its side and measure the widest diameter in centimetres, inches or feet. The calculator assumes the height is 1.3 times the diameter, which matches typical pear bean bag proportions. If your bag is unusually tall or squat, use the box mode with your own length, width and height for a tighter estimate of how much bean bag filling you need.
How many litres are in a cubic foot of bean bag filling?
One cubic foot equals 28.32 litres (28.3168 L exactly). Filling is usually sold by volume in litres in metric countries and by cubic feet in the US and UK, so the calculator shows both. Example: 250 L of filling is 8.83 cu ft, and at the EPS density of 15 kg/m^3 it weighs 3.75 kg.
Is shredded foam heavier than EPS beads for the same bean bag?
Yes, much heavier. 250 L of EPS beads weighs about 3.75 kg, while 250 L of shredded foam weighs about 10.00 kg at 40 kg/m^3. That matters if you move the bag often or hang it in a kids' room. Microbeads sit in the middle at about 5.00 kg for 250 L.
Can I mix different bean bag fillings?
You can, and many people top up an old EPS bag with microbeads to firm it up. Mixing changes the effective density, so the honest approach is to weigh what you already have: the weight readout above works in reverse. In practice, refilling with the same material keeps the feel consistent.
Why do EPS beads stick to everything when I fill a bean bag?
Static electricity. EPS beads are notorious for clinging to hands, clothes and the bag opening. Work in a room without carpet if you can, wipe the opening with an anti-static dryer sheet, and pour through a wide funnel or a cardboard tube. A second pair of hands to hold the inner liner open makes the job far cleaner.
Is bean bag filling flame retardant and safe?
Reputable EPS refill beads are manufactured with a flame-retardant additive and tested to furniture fire-safety standards (for example BS 5852 in the UK). Keep the beads away from small children and pets during filling because they are a choking hazard, and check that the bag's inner liner zips fully closed before use.
How many bags of filling should I buy?
Divide the fill volume by your retail bag size and always round up: a slightly over-full bag is comfortable, a short one means a second delivery. Example: a 70 x 60 x 50 cm box bean bag needs 178.50 L at 85% fill, so 2 bags of 100 L at $13 each costs $26.00. The cost estimator above does this division and the price math for any bag size.
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