Joint Sand Calculator

Measure area, choose pavers, then set joint details. Add pattern, waste, and edging allowances easily. Export results to keep every patio refill simple today.

Calculator
Enter your paving and joint details
Switching units updates labels and typical defaults.
Use manual density for irregular patterns or stones.
Applies suggested values to speed up estimating.
Choose how you want to provide paving area.
Enter a positive length.
Enter a positive width.
Use for triangles/circles after you compute area.
Typical: 200–300 mm (or 8–12 in).
Enter a positive paver length.
Typical: 100–200 mm (or 4–8 in).
Enter a positive paver width.
Fine joints: 2–5 mm. Wider joints need more sand.
Enter a positive joint width.
Often 20–40 mm depending on paver thickness.
Enter a positive joint depth.
Only used when manual method is selected.
Dry sand often ranges 1400–1700 kg/m³.
Enter a positive bulk density.
Accounts for settling after vibration and watering.
Covers spill, sweep-out, and uneven joints.
Herringbone and cuts may need more sand.
Extra for borders, cut pieces, and transitions.
Used to estimate how many bags to buy.
Example data
Sample inputs and outputs
Scenario Area Paver size Joint (W × D) Allowances Sand mass Bags
Backyard patio 20.0 m² 200×100 mm 5×30 mm Waste 8%, Edge 3%, Pattern 1.00 ≈ 110–140 kg 5–6 (25 kg)
Pathway 10.0 m² 300×300 mm 3×25 mm Waste 6%, Edge 5%, Pattern 1.05 ≈ 25–40 kg 2 (25 kg)
Irregular stone (manual) 15.0 m² — 8×35 mm Density 18 m/m², Waste 10% ≈ 160–220 kg 7–9 (25 kg)

Examples are illustrative. Your surface, joint width, and compaction method will change totals.

Formula used
How the estimate is calculated

The calculator estimates joint sand by modeling the joints as long, narrow trenches filled to a selected depth.

Core steps
  1. Area: compute paving area (A).
  2. Joint length density: estimate total joint length per area (J, meters of joint per m²).
  3. Base joint volume: V₀ = A × J × w × d.
  4. Allowances: apply factors for pattern, edges, waste, and compaction: V = V₀ × (pattern) × (1+edge%) × (1+waste%) × (compaction).
  5. Mass: M = V × ρ where ρ is bulk density.
  6. Bags: bags = M ÷ bag_size, then round up.

For the automatic method with rectangular pavers, joint length density is approximated as J ≈ (1/L) + (1/W), where L and W are paver dimensions in meters.

How to use
Step-by-step guide
  1. Select your unit system and area input mode.
  2. Enter the paving size, or your total area.
  3. Add paver dimensions, joint width, and joint depth.
  4. Choose auto method for standard pavers, or manual density for irregular stone.
  5. Adjust allowances for waste, edges, pattern complexity, and compaction.
  6. Press Calculate. Results appear above the form.
  7. Use Download CSV or Download PDF for records.
Best practice notes
  • Dry sweep sand in, compact, then top up and repeat.
  • For polymeric sand, follow the exact watering steps.
  • Buy one extra bag if your joints vary or edges are complex.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.