Concrete calculator
Ready-Mix vs. Bags Cost Calculator
Compare the full entered cost of bags with delivered ready-mix. Include minimum billed volume, short-load charges, mixer rental, and handling; example prices are editable.
Planning estimate, not a contractor quote. Review the assumptions and replace presets with local prices when available.
Method
How this calculator works
Both options start with the same slab volume and material allowance. Bagged concrete rounds to whole packages. Ready-mix rounds to a quarter cubic yard, then applies the supplier’s minimum billed volume and explicit fees. This compares the entered purchasing and handling costs, not a complete installed slab.
Bags total = whole bags × bag price + bag delivery + mixer rental + handling. Ready-mix total = max(order volume, minimum billed volume) × unit rate + delivery + applicable short-load fee + placement. Difference = bags total − ready-mix total.
Worked example
A realistic starting point
For a 10 × 10 ft slab, 4 in deep, with 10% allowance, use 62 nominal 80 lb bags or order 1.50 yd³. At the illustrative defaults, bags cost 62 × $7 + $60 rental = $494. Ready-mix costs 1.50 × $160 + $150 delivery + $75 short-load fee = $465. Bags cost $29 more before any additional costs.
What changes the answer
Factors worth checking
Supplier fees
Request one written price that explains the minimum billed volume, short-load threshold, delivery, waiting time, and return charges.
Whole packages
Changing bag size changes the number of packages. Enter the price for the selected size each time.
Handling and placement
Include transport, helpers, rental, fuel, or pumping if they differ between the two options.
Matching scope
Use the same concrete specification and include comparable tax and service costs in both quotes.
Common questions
Ready-mix vs. bags FAQ
Does a negative difference mean bags are cheaper?
Yes, for the costs entered here. It does not establish whether the pour can be mixed and placed practically.
What does minimum billed volume mean?
A supplier may charge for a minimum amount even if the calculated order is smaller. The delivered order and billed quantity are shown separately.
Are the default prices current quotes?
No. They are examples that demonstrate the calculation. Replace them with the two supplier quotes you are comparing.
Can I compare a project in metric units?
Yes. Select Metric for converted input and output units. Currency remains USD and bag sizes remain the selected nominal US packages.
Evidence
Sources & review
- QUIKRETE Concrete CalculatorManufacturer quantity and whole-bag rounding reference; package data governs yield.
- NRMCA — Concrete in PracticeReady-mix practice and project planning context. Not a source for the example prices.
Published by Calcstead. Report a correction.
Method and source links reviewed September 5, 2026. Price presets are editable planning inputs and should be replaced with current local information.