Border Stone Calculator

Calculator

Run Length *

Total edging length along paths, beds, or driveways (meters).

Stone Length *

Length of one border stone (meters).

Joint Gap (mm)

Spacing between stones for joints (millimeters).

Stone Width *

Front-to-back width (meters).

Stone Height *

Vertical height (meters). Useful for weight and mortar.

Waste Allowance (%)

Extra pieces for breakage, cuts, corners, and spares.

Density (kg/m³)

Typical concrete/stone ~2200–2600 kg/m³.

Currency Code

Example: USD, EUR, GBP, PKR.

Labor Cost per Meter

Optional installation labor rate.

Cost per Stone

If set, used as primary material pricing.

Cost per Meter (Alternative)

Used only when cost per stone is zero.

Mortar Cost per m³

For joint mortar volume estimate (optional).

Include bedding concrete volume

Include joint mortar volume

Toggle optional material estimates for a more complete takeoff.

Bedding Width (m)

Trench or bed width for concrete bedding.

Bedding Depth (m)

Typical bedding depth 0.05–0.15 m.

Concrete Cost per m³

Used only when bedding is enabled.

Tip: For corners and curves, increase waste allowance slightly.

Example Data Table

Scenario	Run Length (m)	Stone Length (m)	Gap (mm)	Waste (%)	Purchase Stones (pcs)
Garden bed edging	18.0	0.50	8	7	39
Walkway border	32.0	0.40	10	8	87
Driveway edge	45.0	0.60	6	10	83

Values are illustrative. Actual needs vary with layout, cuts, and site conditions.

Formula Used

1) Stone count (installed):

n = ceil((L + g) / (s + g))

L = run length (m)
s = stone length (m)
g = joint gap (m)

2) Purchase stones (with waste):

n_buy = ceil(n × (1 + w/100)), where w is waste percentage.

3) Volume and weight:

V_each = s × w × h, V_total = V_each × n_buy, Mass = V_total × ρ

w = stone width (m), h = stone height (m)
ρ = density (kg/m³)

4) Optional joint mortar volume:

V_mortar = (n − 1) × g × w × h

5) Optional bedding concrete volume:

V_bed = L × b × d, where b is bedding width and d is bedding depth.

How to Use This Calculator

Measure the full border run length along the project line.
Enter your stone length, width, and height from the product spec.
Set a realistic joint gap based on your installation method.
Add a waste allowance for cuts, corners, and breakage.
Optionally enable bedding and mortar to estimate supporting materials.
Click Calculate to view results above the form.
Use Download CSV or Download PDF for sharing.

Professional Notes

1) What border stones control

Border stones define edges for lawns, beds, and paving, creating a fixed line that resists lateral soil movement. Typical curb-style pieces range from 0.40–0.60 m long, 0.08–0.15 m wide, and 0.15–0.25 m high. Your selected dimensions strongly influence count, transport weight, and bedding needs.

2) Measurement strategy

Measure the run along the finished alignment, not the rough excavation. For curves, use a flexible tape or string line, then add 3–8% extra length depending on radius tightness. If you have multiple segments, sum all segments and keep a separate note for corners, transitions, and driveway flares.

3) Joint gap selection

Dry-laid edging often uses 3–10 mm gaps to accommodate minor dimensional variation. Mortared edging may tighten gaps to 2–6 mm for appearance, but still needs a workable tolerance. Larger gaps increase mortar volume, while near-zero gaps increase cutting time and risk of chipping.

4) Waste allowance and cutting

Waste covers breakage, trimming, and offcuts that cannot be reused. Straight runs with minimal corners commonly use 5–8% waste. Complex shapes, frequent corners, or miters can require 10–15%. Ordering in full pallet multiples can also influence the final purchase quantity.

5) Bedding concrete guidance

A stable base reduces settlement and rocking. Bedding widths often fall between 0.20–0.30 m, with depths around 0.05–0.15 m depending on soil and load exposure. The calculator estimates bedding volume as length × width × depth, helping you plan ready-mix deliveries or bag quantities.

6) Mortar volume interpretation

Joint mortar is calculated from the number of joints times gap × stone width × stone height. This is a geometric estimate; actual usage can increase due to tooling, voids, or imperfect stone faces. For rough stone, consider increasing mortar cost or adding a contingency factor.

7) Weight and handling logistics

Weight is computed using total stone volume and density. Concrete and many stones sit near 2200–2600 kg/m³, so even small pieces add up quickly. Use the total weight figure for truck sizing, crew handling planning, and verifying whether mechanical assistance is required on site.

8) Cost benchmarking and reporting

Material cost can be priced per piece or per meter, then combined with labor, bedding concrete, and mortar. Track costs separately so you can negotiate supplier pricing while keeping installation productivity visible. Exported CSV and PDF reports support procurement, approvals, and daily crew briefings with consistent numbers. Keep unit rates current to reflect local seasonality and fuel.

FAQs

1) Should I measure before or after excavation?

Measure the finished alignment at the surface line. Excavation lines can shift during grading and compaction, which can change the true run length and the final stone count.

2) What joint gap is most common?

For dry-laid edging, 3–10 mm is typical. For mortared edging, 2–6 mm often looks cleaner while still allowing tolerance for stone size variation.

3) How much waste should I add for corners?

A simple rectangular bed often needs 5–8%. Lots of corners, curves, or miters may require 10–15% because offcuts are harder to reuse.

4) Does the calculator handle curves accurately?

It uses total run length, so accuracy depends on your measurement. For tight curves, measure with string along the curve and increase waste slightly.

5) Why does enabling mortar increase cost noticeably?

Mortar volume scales with joint count and stone height. Taller stones and larger gaps create more joint volume, and mortared work can also raise labor time.

6) What bedding depth should I use?

Many landscape borders use 0.05–0.10 m, while areas with softer soils or higher loads may benefit from 0.10–0.15 m. Follow local practice and site conditions.

7) How do I use the weight estimate?

Use it to plan transport and crew handling. Large totals may require multiple trips, a larger vehicle, or mechanical assistance to reduce fatigue and damage.