Measured Annular Pipe Void Fill Bag calculator.
Subtract a supplied pipe displacement from a measured circular surrounding void and order material by mixed bag yield.
Your inputs
Use measurements from your plan and properties from your chosen product. Any prefilled values are illustrative.
A clear estimate starts here.
Enter your dimensions and product details to see the quantity and purchase breakdown.
Formula and assumptions
How this calculation works.
Fill volume = Σπ(void diameter² − pipe outer diameter²) × length × count / 4. Does not specify fire stopping, structural grout, seals, required clearance or material suitability.
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Chosen product mixed yield per bag
- 10 L/bag
- Measured surrounding void diameter
- 0.2 m
- Supplied displaced pipe outer diameter
- 0.1 m
- Measured filled length
- 1 m
- Identical voids
- 1
Supplied fill product bags: 3 bags
Pure displacement arithmetic; no required clearance or approved sealing detail is inferred.
Before you purchase
Use dimensions from your plan and properties from your chosen product. Any design spacing, section or fixing pattern must already be specified.
Does not specify fire stopping, structural grout, seals, required clearance or material suitability.
All dimensions, properties and application patterns are user-supplied. No building-code default is inserted.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-06. Calculation and review policy.