FIBC Bag Volume & Dimensions Calculator
Use this FIBC bag calculator to estimate rectangular big bag volume from internal filled dimensions, or the filling height required for a target product mass and bulk density.
Use a saved product specification (optional)
Enter your values
First time using this calculator?
Replace the example values with figures from your supplier sheet or measurements. Choose the unit beside each value. Results update as you type; fix any highlighted field before using the result.
GSM means grams per square metre. Net weight excludes the core and other packaging. MOQ means the minimum order quantity. An optional field can stay blank unless the result you need depends on it.
Prices keep the selected currency; changing its label does not convert an exchange rate. Save or export the result after checking your inputs.
Theoretical internal volume
Rectangular internal filled geometry only. Bulging, settling, liners, seams and headspace can change usable volume.
This estimates volume and filling height, not fabric cutting dimensions or safe working load. Confirm the supplier specification separately.
Volume = internal length × internal width × filling height; liters = m³ × 1,000
0.972 m³ = 972 L; height = 1.2 mSaved calculations stay in this browser. No account or cloud backup is created.
Save to a product project (optional)
Choose or create a saved product project ↗This is an illustrative example. Saved or transferred values must be checked against your job.
Calculated from your inputs. Confirm specifications with your supplier.
How sensitive is this result to your assumptions?
Vary one input and inspect theoretical internal volume
All other entered inputs stay fixed. Ranges are your scenarios, not statistical confidence or supplier performance predictions. This uses the same validated calculator engine.
The formula, made clear.
A big bag volume calculation starts with the internal filled footprint and the usable filling height. Multiply these dimensions in meters to estimate cubic meters, then multiply by 1,000 for liters. To plan a height for a product quantity, divide its mass by its measured bulk density and then by the bag footprint. Flexible walls, settling and headspace affect actual usable capacity, so verify the proposed dimensions with the bag supplier before purchasing.
How to use this calculator
- 01
Choose volume from dimensions or filling height from product mass.
- 02
Enter internal filled length and width, selecting the appropriate units.
- 03
Enter filling height, or target mass and the actual product bulk density.
- 04
Review volume in m³ and liters and the calculated internal filling height.
A calculation you can check
A 900 × 900 × 1,200 mm internal fill gives 0.9 × 0.9 × 1.2 = 0.972 m³, or 972 liters. For 1,000 kg at 800 kg/m³, required volume is 1.25 m³ and height on the same footprint is 1.25 ÷ 0.81 = 1.5432 m. This does not establish that the bag is rated to carry 1,000 kg.
- Internal filled length
- 900 mm
- Internal filled width
- 900 mm
- Internal filling height
- 1200 mm
0.972 m³ = 972 L; height = 1.2 mFrequently asked questions
How do I calculate FIBC bag volume?
Multiply internal filled length, width and filling height in meters for a rectangular estimate in m³. Multiply by 1,000 to convert to liters.
How big is a one-tonne bulk bag?
There is no universal size: 1,000 kg at 800 kg/m³ needs 1.25 m³, while at 500 kg/m³ it needs 2 m³. Dimensions and permitted load require the supplier specification.
Does this calculate safe working load or cutting dimensions?
No. It estimates rectangular internal volume and filling height. Fabric cutting dimensions, lifting performance and safe working load require a separate technical specification.
Check the displayed formula and units against your quotation. Use measured GSM, net weight and actual layout dimensions where available. Default densities are planning assumptions, not certified material properties. Calculated cost does not certify strength, compatibility or safe loading.
Method, units and material assumptions ↗