FIBC Fill Weight from Volume Calculator
Estimate FIBC product fill weight from internal big bag volume, actual bulk density and an explicit headspace allowance. Review kilograms and metric tonnes before choosing an approved planned fill.
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.
Help with actual product bulk density
Density is material mass per unit volume. A typical preset is suitable for an early estimate; use the supplier grade value for purchasing decisions.
Estimated product fill mass
Headspace is a fraction of internal volume, not a height allowance.
Estimated mass is not a safe working load. Check the approved bag rating and application before choosing planned fill.
Fill mass = internal volume × (1 − headspace/100) × product bulk density
1.25 × (1 − 10/100) × 800 = 900 kgSaved 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 estimated product fill mass
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.
Bulk density connects the space occupied by a loose product to its mass. Enter a value measured for the product in its intended filling condition; solid material density is a different property. This estimate reserves a specified share of bag volume for headspace before multiplying by bulk density. A geometric estimate can exceed the bag rating, so use the verified specification to select the permitted operating fill rather than treating the calculated mass as a load approval.
How to use this calculator
- 01
Enter internal volume from the FIBC volume calculator or a verified filled-volume measurement.
- 02
Enter product bulk density in kg/m³ for the planned filling condition.
- 03
Enter the percentage of internal volume reserved for headspace.
- 04
Review estimated fill mass and confirm the proposed fill against the approved bag specification.
A calculation you can check
At 1.25 m³, 800 kg/m³ and 10% volume headspace, usable volume is 1.125 m³ and estimated product mass is 900 kg, or 0.9 tonnes. With no allowance the geometric estimate is 1,000 kg; the approved operating fill still requires separate confirmation.
- Internal bag volume
- 1.25 m³
- Actual product bulk density
- 800 kg/m³
- Volume reserved for headspace
- 10 %
1.25 × (1 − 10/100) × 800 = 900 kgFrequently asked questions
How do I calculate bulk bag fill weight?
Multiply usable internal volume in m³ by product bulk density in kg/m³. Deduct the entered volume headspace allowance before multiplying.
Can calculated fill weight replace the safe working load?
No. Volume and density estimate product mass; the permitted fill depends on the verified bag rating and approved application.
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 ↗