Blast Hole Pattern & Charge

Wrong burden or spacing means flyrock, poor fragmentation, or wasted explosive. This calculator designs safe, efficient blast patterns based on hole diameter, rock type, and bench geometry. Enter hole diameter, depth, bench height, face width, subdrill, stemming, rock hardness (soft to very hard), and pattern type (rectangular, staggered, triangular). Calculates burden, spacing, total holes, rows and holes per row, powder factor, charge per hole, total charge weight, and total drill footage. Rock hardness presets for limestone, shale, sandstone, slate, granite, basalt, and quartzite with industry-standard burden multipliers. Shows powder factor with safety threshold warning. KEY FEATURES: - Three pattern types with layout preview - Powder factor calculation and warning - Subdrill and stemming sizing - Total drill footage estimate - Works completely offline Built for drill and blast engineers, quarry operators, and mining contractors.