Concrete Mix Design (Simplified)
Water-to-cement ratio interpolated from ACI 211-style curves; cement, coarse, fine aggregate per cubic yard.
Example
You enter
- Target strength (psi) 4000
- Exposure class interior
- Max aggregate (in) 1
- Slump (in) 4
You get
- Water-to-cement 0.570
- Water (lb/yd³) 325
- Cement (lb/yd³) 570.18
- Cement (bags/yd³) 6.07
- Coarse agg (lb/yd³) 1,700
- Fine agg (lb/yd³) 1,405
Checked against published worked examples from: ACI.
Details, formula, and sources
Formula or tableACI 211 simplified: w/c ratio interpolated by target strength and exposure class; water content from aggregate size + slump; cement = water / w_c; coarse aggregate a fixed 1,700 lb/yd^3; fine aggregate = 4,000 lb/yd^3 total - water - cement - coarse (simplified weight method, not absolute volume).
Source and editionACI 211.1 (Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete) by name.
Free accessACI 211 licensed; principles free in published concrete texts.
What governsEstimate. AHJ and licensed structural engineer govern.
API field namesstrength_psi, exposure, max_aggregate_in, slump_in, wc_ratio, water_lb_yd3, cement_lb_yd3, cement_bags_yd3, coarse_lb_yd3, fine_lb_yd3
- Curve table data/construction/aci-211-curves.json keyed to strength / exposureACI 211 by name