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Calculate natural flagstone, sand, and mortar for patios & walkways
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A flagstone calculator helps you estimate the tonnage of natural stone needed for patios, walkways, and other hardscape projects. Unlike manufactured pavers with uniform sizes, flagstone is sold by weight and coverage varies significantly based on stone type and thickness.
The general rule is that 1 ton of flagstone covers 80-100 square feet at typical thicknesses (1-2 inches). This calculator accounts for:
Example: 120 sq ft ÷ 90 coverage × 1.10 waste = 1.47 tons of bluestone
1" thick flagstone weighs ~14 lbs/sq ft; 2" thick weighs ~28 lbs/sq ft
| Stone Type | Coverage | Thickness | Characteristics |
|---|---|---|---|
| Bluestone | 85-90 sq ft/ton | 1-2" | Blue-gray, very durable, consistent thickness |
| Arizona | 90-100 sq ft/ton | 1-1.5" | Tan/gold colors, thinner, affordable |
| Sandstone | 75-85 sq ft/ton | 1.5-2" | Warm tones, softer, easier to cut |
| Slate | 95-105 sq ft/ton | 0.5-1" | Dark colors, thin, can be slippery wet |
| Limestone | 80-90 sq ft/ton | 1.5-2" | Gray/cream, formal look, etches with acid |
| Quartzite | 75-85 sq ft/ton | 1-2" | Very hard, sparkly, premium price |
Most common method. Stones set on 1" sand bed over 4" compacted gravel base. Joints filled with polymeric sand or decomposed granite.
Stones set in mortar bed over existing concrete slab. Joints grouted. Most permanent but requires skill. Best for formal patios.
Individual stones set directly into lawn with 2" sand bed underneath. Grass grows between. Casual, natural look.
Visit the stone yard and select pieces yourself. You can choose better colors and avoid problem pieces.
Natural stone varies. Extra allows for cutting waste, future repairs, and matching pieces that work together.
Stone is heavy. Ensure delivery truck can access your property. Pallets can't be moved by hand.
Request consistent thickness (±1/4") for easier installation. Mixed thicknesses require more bed adjustments.
Large flagstones can weigh 100+ lbs each. Plan for helpers or equipment to move them.
Sealers enhance color and protect from stains but require reapplication. Many prefer the natural patina.
One ton of flagstone typically covers 80-100 square feet at standard thicknesses (1-2 inches). Thinner stone covers more area; thicker stone covers less.
Bluestone is the most popular for patios due to its durability, consistent thickness, and blue-gray color. Pennsylvania bluestone is considered premium quality.
Yes, with a diamond blade in a circular saw or angle grinder. Score and snap for straight cuts. Wear safety glasses and dust mask. Complex curves require professional tools.
For patios and walkways, 1.5-2 inches is ideal. Thinner stone (under 1 inch) may crack under pressure. Stepping stones in grass can be 1-1.5 inches.
Some types (especially polished slate) can be slippery. Textured surfaces like sandstone and natural-cleft bluestone provide better traction. Avoid smooth finishes near pools.
Properly installed flagstone can last 50+ years. The stone itself is nearly indestructible; usually the base or joints need attention before the stone does.