Concrete Bag Calculator

Each bag of pre-mixed concrete yields a specific volume of cured concrete. Bag yields below are the manufacturer-published figures published by Quikrete and Sakrete — the two largest US suppliers — and are identical for these sizes.

A cubic yard equals 27 cubic feet, so the bags-per-yard count comes from 27 ÷ yield. Lighter bags pour quicker but stack heavier per cubic yard; heavier bags need fewer trips but each weighs more.

Calculate bag count by dividing total cubic feet of concrete needed by the cubic-foot yield per bag, then rounding up.

Quikrete and Sakrete publish identical yields for their standard pre-mix bags. Differences appear in specialty mixes — fast-setting, fiber-reinforced, high-strength, and crack-resistant blends — where aggregate gradation and water demand vary slightly. For volume planning purposes the standard mix figures apply to both brands.

Slide the cubic-yard input to see how the same volume translates into 40-pound, 50-pound, 60-pound, and 80-pound bag counts — with total weight and estimated retail cost for each option.

The crossover point sits at roughly 1 cubic yard. Below that, bagged usually wins on cost and convenience. Above, concrete mixer trucks deliver faster, cheaper, and at more consistent strength.

• Use bagged concrete for: post holes, small footings, small patios under 100 sq ft, repairs, and stair tread pours.
• Use ready-mix for: driveways, garage slabs, large patios, foundations, and any pour over ~1 yd³ (about 60 × 60 lb bags).
• Include mixer rental, power or fuel, cleanup, and handling time when comparing bagged concrete with delivery.
• Hand-mixing more than 30 bags in a day is hard physical work; rent a mixer or call ready-mix.

Pre-mixed bags need only water added. Standard ratios per bag:

Add water gradually to hit a workable consistency — a peanut butter texture that holds shape on a trowel without crumbling. Over-watering reduces final strength and yield.

Pre-mixed concrete bags last 6–12 months when stored dry, sealed in their original plastic wrapping, and kept off the floor on pallets. Once opened or exposed to humidity, the cement hydrates prematurely and the bag forms hard lumps that degrade strength. Discard any bag with hard chunks.