Calculator
How many sacks do I need?
Measure the cover, pick the shape, and we work out the litres at a comfortable fill and round up to whole sacks. Send the result straight to us as a quote request.
For an empty cover, leave existing litres at 0. For a top-up, enter your best estimate of usable filling already inside. Dimensions should describe the filled cover, not the fabric laid flat.
Your estimated additional filling
238 litres
1 × 250 L sack · about 12 L left over
EPS or EPP regrind
R150
Virgin beads
R400
A geometric estimate, not a guaranteed fit or final quote. Seams, curves and how you sit affect the amount. Sack prices exclude delivery. Workshop refills are charged by measured weight, from R49.00/kg for regrind.
How the calculation works
Dimensions in cm: rounded = π × width × depth × height ÷ 6, cylinder = π × diameter² × height ÷ 4, box = width × depth × height. Divide by 1,000 for litres, apply the fill percentage, subtract existing litres per cover (minimum zero), multiply by the number of covers, then round up to whole 250 L sacks.
Measuring and filling
- How do I measure the cover?
- Use the cover manufacturer's filled dimensions or capacity when available. Otherwise measure the intended filled width, depth and height without stretching the cover. For a cylinder, measure diameter and height. Flat fabric measurements are not filled dimensions and can overestimate capacity. Irregular loungers are only approximations: ask the workshop if unsure.
- Why 80% and not full?
- Beads need room to move so the bag moulds around you. A cover stuffed to 100% sits like a drum and stresses the seams. Most people are happiest between 75% and 85%.
- What does a 250 L sack look like?
- Think bigger than a typical black bin bag: this is a 250-litre sack, about 900 mm tall and 600 mm across, weighing 4–5 kg. Bin bags vary in size, so this is only a visual comparison. 4 sacks is roughly a cubic metre.
- Will a sack fit in my car?
- It depends on the car. In a standard-size car, you may only fit one sack on the back seat. Measure your available space and the door or boot opening before collecting, using the approximate sack dimensions of 900 mm tall by 600 mm across. We cannot guarantee a fit.
- I have a 130 × 180 cm lounger. How much?
- Two measurements alone are not enough. If those are filled dimensions and the rounded cover is 80 cm high, an ellipsoid estimate at 80% fill is about 784 litres, or four sacks. Flat cover measurements must not be used as filled dimensions. Shape and actual height materially change the result.
Skip the pouring.
Bring the cover to the workshop and we fill it while you wait, priced by the kilogram.