Gravel & Concrete Pro: Dual Material & Slab Utility

Mainstream construction calculators cost $49–$80/year in subscriptions or charge expensive licensing fees, require network accounts, and fail to calculate dual-material jobs simultaneously. Concrete contractors, landscapers, driveway builders, patio DIYers, and masons need an instant on-the-spot Android tool to calculate both the compacted gravel/crushed stone sub-base (in tons and cubic yards using real aggregate bulk densities) AND the poured concrete slab/footing volume, ready-mix delivery truck sizing, dry 60/80-lb bag counts, and rebar grid linear footage simultaneously 100% offline. Core Features: • Dual-Material Takeoff Engine: Simultaneously computes gravel/crushed stone sub-base and poured concrete slab/footing in a single calculation • True Bulk Density Matrix: Converts cubic yards to tons using specific densities for Crusher Run (1.45 t/yd³), #57 Stone (1.40 t/yd³), Pea Gravel (1.35 t/yd³), Coarse Sand (1.30 t/yd³), and DG (1.50 t/yd³) • Compaction Allowance Factor: Built-in 5% to 15% subgrade vibratory plate compaction expansion so you never come up short at the quarry • Concrete Slab, Trench & Footing Calculator: Instant volume in Cubic Yards and Cubic Feet with adjustable 5%–15% waste spillage buffer • Ready-Mix Truck Sizing vs Bag Counter: Immediate dispatch sizing (full 9.0–10.0 yd mixer trucks) or exact retail bag counts (60-lb and 80-lb Quikrete/Sakrete bags) • Rebar Grid & Mesh Estimator: Calculates #4/10M rebar grid linear footage and 20ft stick counts for 12", 18", or 24" on-center spacing • Material Cost Takeoff: Enter local quarry ton price and ready-mix yard price for instant combined job estimates • Offline PDF Estimate Export: Generate clean, professional PDF material estimates on the jobsite with zero internet • 100% Offline & Sovereign: Zero cloud dependencies, zero ads, zero recurring fees, perpetual white-label commercial rights 100% Offline • 75% Less Than Mainstream Subscriptions • Zero Cloud Accounts Required.