Calculator Inputs
Formula Used
Cross-sectional area depends on the selected profile:
- Rectangular: Area = width × depth
- Triangular: Area = 0.5 × width × depth
- Circular: Area = π × (diameter / 2)2
Base sealant volume (mL) = Area (mm²) × Length (mm) × Applications × Fill fraction ÷ 1000
Adjusted volume (mL) = Base volume × (1 + Waste %) ÷ Utilization fraction
Coverage per cartridge (m) = Cartridge size (mL) × 1000 ÷ Area (mm²) ÷ 1000
Cartridges required = Ceiling(Adjusted volume ÷ Cartridge size)
How to Use This Calculator
- Select metric or imperial units to match your drawings or field notes.
- Choose the sealant profile that best matches the intended firestop geometry.
- Enter width, depth, and total linear length for one or multiple similar applications.
- Add fill percentage if the space is not fully filled with sealant.
- Include waste and usable output adjustments for site handling and cartridge loss.
- Enter cartridge size and cost to estimate purchasing quantities and budget.
- Press the calculate button to display the result above the form and view the graph.
- Use the CSV or PDF buttons to export the planning summary.
Example Data Table
| Scenario | Profile | Width | Depth | Length | Waste | Cartridge | Estimated Cartridges |
|---|---|---|---|---|---|---|---|
| Cable tray sleeve | Rectangular | 20 mm | 20 mm | 15 m | 10% | 300 mL | 3 |
| Pipe annular seal | Circular | 25 mm | 25 mm | 8 m | 12% | 600 mL | 1 |
| Wall joint edge | Triangular | 18 mm | 18 mm | 22 m | 8% | 300 mL | 2 |
Frequently Asked Questions
1. What does this calculator estimate?
It estimates sealant volume, adjusted material needs, cartridge count, rough cost, and cartridge coverage for simple firestop planning scenarios.
2. Can I use this for code compliance?
No. Use it for planning only. Final compliance depends on the tested assembly, approved listing details, substrate conditions, and installation instructions.
3. Why include waste allowance?
Waste accounts for nozzle trimming, purge loss, uneven field application, partial cartridges, and handling inefficiencies that affect real material demand.
4. What is usable cartridge output?
It reduces theoretical cartridge capacity to reflect the portion you can actually dispense and place effectively during field installation.
5. When should I use the circular option?
Use it when the sealant fills an annular or round gap. The calculator treats the smaller entered dimension as the effective diameter.
6. What if my joint depth differs from width?
Enter the actual installed depth. Sealant quantity depends on cross-sectional area, so both dimensions directly affect material volume.
7. Can I estimate several identical penetrations together?
Yes. Increase the number of similar applications. The calculator multiplies the sealant demand before applying waste and utilization adjustments.
8. Does this include backing material or mineral wool?
No. This page estimates sealant only. Backing rod, mineral wool, collars, sleeves, labor, and inspection costs must be assessed separately.