A worked planning guide
How Much Extra Paver Material Should You Buy?
Work through rectangle and L-shaped patio examples to separate cut waste, spare stock and rounded purchase counts before checking supplier pack sizes.
Start with source pavers, then add spare stock
The rectangular example needs 1,091 source pavers in its layout. A 10% allowance produces 1,201 to buy: 110 additional pavers after rounding. Its 5.5% geometric waste is a different measurement, not another percentage to add to that purchase count.
BuildPlot can calculate those quantities. It cannot determine the right spare percentage for every project: handling, unusable cuts, breakage and the stock you want for future repairs are not all captured by geometry.
Three quantities that should stay separate
- Geometric waste
- The face area discarded when source pavers are clipped at the boundary, divided by the original face area of all layout sources.
- Layout source count
- Whole pavers plus cut sources. A half-paver at an edge still consumes one source paver in this conservative model.
- Spare allowance and purchase count
- Additional stock applied to the source count. Purchase = round up [layout sources × (1 + spare percentage)]. Rounded extra stock = purchase − layout sources.
Adding the geometric waste percentage again to a source-based count would mix an area ratio with a piece count that already includes the cut sources. An area-only estimate uses a different starting point and should not be treated as the same calculation.
Rectangle versus an L-shaped patio
Both use the same 12 × 20 ft outside rectangle, 4 × 8 in pavers, Running Bond and a ⅛ in joint. The L-shape removes a 4 × 6 ft cutout at the screen-bottom-right. The buttons open each full project at a 10% spare allowance.
Rectangle
240 sq ft · 986 whole + 105 cut sources · 5.5% geometric waste.
Use this example → RectangleL-shape: 4 × 6 ft cutout
216 sq ft · 878 whole + 105 cut sources · 5.5% geometric waste.
Use this example → L-shape: 4 × 6 ft cutout| Shape | Layout sources | Cut sources | Geometric waste | Buy at 5% | Buy at 10% | Buy at 15% |
|---|---|---|---|---|---|---|
| Rectangle | 1091 | 105 | 5.5% | 1146 | 1201 | 1255 |
| L-shape: 4 × 6 ft cutout | 983 | 105 | 5.5% | 1033 | 1082 | 1131 |
The L-shape covers less area, but in this example its cut-source count is the same as the rectangle’s: 105. Removing area does not scale every result proportionally. The actual rows, offsets and internal corner matter.
Check the buffer before rounding to a supplier pack
Use the 5%, 10% and 15% columns as scenarios, not as installation recommendations. A larger buffer increases extra stock without changing the drawing or its geometric waste. In the rectangular example, changing from 5% to 15% changes the purchase count by 109 pieces.
After choosing a buffer, ask how the product is sold. If a supplier’s confirmed pack contains P pavers, a pack-based order is round up [purchase count ÷ P] packs. The calculator does not know pack coverage, return rules, border-unit quantities or prices; verify those before turning a planning count into an order.
What this model leaves out
Offcuts are not reused automatically, so the source count can exceed a carefully optimized cutting plan. Geometric waste does not predict handling losses, broken pavers or color selection. Base and bedding depths remain separate editable planning inputs; spare pavers are not an aggregate or sand allowance.
These examples use straight, measured boundaries and a fixed pattern origin. They do not cover arbitrary polygons, curves, borders made from a different product or labor. Actual face dimensions, joints and finished boundaries can change the result. Compare a model with your product specification and site measurements before ordering.