Concrete Mix Design
Calculators
Get the proportions right before you pour. Eight free tools covering every mix design variable — from the fundamental cement-to-aggregate ratio and water-cement ratio, to batch scaling, admixture dosing, pigment loading, fiber reinforcement, and air entrainment for freeze-thaw durability.
Mix Design Calculators
Every variable in a concrete mix design has a knock-on effect. Use these tools together — start with your target strength, find your w/c ratio, calculate cement content, then size your batch.
The foundation of every mix design. Enter your target compressive strength (psi or MPa) and the calculator outputs the cement:sand:aggregate ratio by weight and volume — for standard mixes (1:2:3, 1:1.5:3), nominal mixes (M15 through M50), or custom proportions. Outputs include material quantities per cubic yard or cubic meter for any batch size.
The single biggest lever on concrete strength and durability. Enter your target strength and exposure class — the calculator outputs the maximum allowable w/c ratio per ACI 318 and the corresponding water and cement quantities per cubic yard.
Know exactly how many bags — or how many pounds — of cement your mix needs. Input your target strength, volume, and water-cement ratio; outputs include cement by weight, bag count (40/60/80/94 lb), and cost estimate based on your local price per bag.
Scale a mix design up or down to any batch size — mixer drum capacity, truck load, or total project volume. Enter your proportions once; the calculator outputs the exact weights of cement, sand, aggregate, and water for any number of batches.
Convert manufacturer dosage rates (oz/100 lbs cement or mL/100 kg) to exact quantities for your batch. Covers water reducers, superplasticizers, accelerators, retarders, and corrosion inhibitors — with guidance on compatibility and stacking multiple admixtures.
Calculate pigment loading by weight percentage of cement content for consistent color across multiple batches. Outputs pigment quantity in lbs and kg, with guidance on typical loading rates (2–10% of cement weight) and color intensity by pigment type.
Determine fiber dosage in lbs/yd³ or kg/m³ for polypropylene, steel, glass, and synthetic fibers. Enter your concrete volume and target dosage rate — outputs include total fiber weight and bag count by fiber type for your pour.
Calculate the required air content percentage and air-entraining admixture dosage for your exposure category. References ACI 318 Table 19.3.3.1 target air ranges (3.5–7.5%) by aggregate size and exposure class, then back-calculates admixture volume for any batch size.
Why Mix Design Is the Most Important Step You Can Take Before Pouring
Volume tells you how much concrete you need. Mix design tells you what that concrete will actually do. A slab poured with the wrong water-cement ratio can lose 30–40% of its potential compressive strength — and no amount of curing time will get it back. The mix design decisions made before the truck arrives determine the final strength, durability, permeability, and finish quality of everything that gets placed.
The most common field mistake is adding water at the truck. Every extra liter of water per 100 kg of cement raises the w/c ratio, reduces strength, increases shrinkage cracking, and worsens freeze-thaw resistance. Our Water-Cement Ratio Calculator shows you exactly how much strength you're trading away at any given w/c ratio, before you decide to adjust workability.
For decorative or specialty applications — stamped concrete, colored flatwork, fiber-reinforced industrial floors — the additional mix design tools here handle admixture dosing, pigment loading, and fiber reinforcement rates so each batch is consistent. Inconsistent batching is why color concrete jobs end up with visible patchwork between pours. Use the Batch Calculator to lock in proportions and run every mixer load the same way.
Mix Design for Every Situation
From DIY bag mixing to ready-mix spec review, these calculators work for any scale of project.
DIY Homeowners Mixing Bags
Mixing Quikrete or Sakrete on site? The Cement Quantity and Batch calculators tell you exactly how many bags to buy and how much water to add — so you don't guess at the ratio and end up with weak concrete.
Contractors Reviewing Ready-Mix Specs
Verify that your ready-mix supplier's mix design meets the specified w/c ratio and cement content for the exposure class on the project. Use the w/c Ratio and Air Entrainment calculators to cross-check delivery tickets against spec requirements.
Decorative & Specialty Concrete
Stamped, colored, and fiber-reinforced concrete jobs require consistent batching across every pour. Use the Pigment Calculator to nail color loading and the Fiber Calculator to dose reinforcement accurately — so there's no mismatch between the first and last truck.
Mix Design FAQ
Need Volume Calculations Too?
Mix design tells you what concrete to use. Flatwork and foundation calculators tell you how much to order.