Calculated result
62bags
Concrete bags to order
Formula
CONC-BAG-001L × W × D × (1 + waste) ÷ bag yield
33.33 ft³
Net pour volume
1.23 yd³
Net volume
36.67 ft³
Material including waste
Concrete calculator
Concrete bag calculator
Slab volume translated into a whole-bag purchase quantity using the stated bag yield.
By Feroz Sheikh · Formula CONC-BAG-001 v1.0.0 · Tested formula
Formula
CONC-BAG-001v1.0.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Refine measurements and rates at any time. Your current values are included in the material-list PDF.
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
This calculator converts a rectangular pour into whole bags using the yield printed on the sack, plus a visible waste factor. Formula CONC-BAG-001 v1.0.0. Add the bags to an estimate and compare the full cost with a local ready-mix quote, including mixing, equipment, minimum-order and delivery charges. Use the yield on the bag in your hand.
- Measure the finished pour length, width and depth.
- Enter the yield stated on the selected bag rather than assuming every bag performs the same.
- Apply the visible allowance before whole-bag rounding.
Size chart
Bagged-concrete chart (4 in, 0.60 ft³ yield, 10% waste)
Use the yield printed on the sack. Compare full local quotes, including mixing, minimum-order and delivery costs, before choosing bags or a truck.
| Pad | Primary | Check |
|---|---|---|
| 4 × 4 ft | 10 bags | 5.33 ft³ |
| 6 × 6 ft | 22 bags | 12 ft³ |
| 8 × 8 ft | 40 bags | 21.33 ft³ |
| 10 × 10 ft | 62 bags | 33.33 ft³ |
Metric example — 3 × 3 m pad. A 3 × 3 m pour at 100 mm with 10% waste returns 59 bags. Use the yield on the bag.
- Volume method. Length × width × depth, or cylinder volume for holes. Ready-mix is still ordered by volume. Concrete Network — volume calculation guidance
- Bag yield. Use the yield printed on the sack. Bags belong on small pads and post holes. Sakrete — estimating bagged concrete jobs
Add your project costs
Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.
Enter your supplier’s ready-mix concrete rate in the selected unit. Add delivery, pumping, short-load fees and placing labour as separate project costs. For GCC projects, select QAR, AED, SAR, KWD, OMR or BHD and enter local supplier rates.
How this calculator works
A transparent concrete bag calculator takeoff.
Feroz SheikhWritten by Feroz Sheikh · founder
This calculator converts a rectangular pour into whole bags using the actual yield published for the selected bagged-concrete product.
Bag counts use the yield printed on the selected product. Compare the whole-bag quantity and mixing costs with a local ready-mix quote for the same waste-adjusted pour; bag weight alone does not establish yield or the cheaper supply method.
Worked example. Example: a 10 ft × 10 ft pour at 4 in depth contains 33.33 ft³. With 10% waste and a 0.60 ft³ bag yield, the purchase quantity rounds to 62 bags.
See the example inputs and calculated result
This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.
| Input | Example value |
|---|---|
| Pour length | 10 ft |
| Pour width | 10 ft |
| Concrete depth | 4 in |
| Bag yield | 0.6 ft³ / bag |
| Waste factor | 10 % |
Example result: Concrete bags to order — 62 bags.
L × W × D × (1 + waste) ÷ bag yield
Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.
- 1. Measure the finished pour length, width and depth.
- 2. Enter the yield stated on the selected bag rather than assuming every bag performs the same.
- 3. Apply the visible allowance before whole-bag rounding.
Field notes that change the number
- Yield is a labelled volume, not the bag weight. Replace the default if the sack in your hand says otherwise.
- There is no universal one-yard cost break-even. Compare bag price, mixing time and equipment with the supplier’s minimum billable quantity, delivery and short-load charges.
- Check access, placement time and the specified mix before choosing bags or delivery for this pour.
Common mistakes
- Mixing bag brands in one pad and wondering why the colour and set do not match.
- Using 80 lb counts while buying 60 lb sacks.
- Skipping waste because “it is only bags.”
Need the broader workflow? Read the concrete planning guide.
How-to: Concrete for solid tube forms: diameter, height and tube count · How to calculate a concrete slab · Ready-mix or bags: when each makes sense · How to fill fence and deck post holes
Questions
Questions about concrete bag calculator
Can I use any bag yield?
Use the yield shown by the exact product manufacturer; bag size alone does not guarantee the same yield.
When should I use ready-mix instead?
Supplier delivery suitability depends on job scale, access, timing and local availability; obtain a supplier quote.
How many bags of concrete for a 10x10 slab?
A 10 × 10 ft pour at 4 in, 0.60 ft³ bag yield and 10% waste returns 62 bags. Compare the full bag-mixing cost with a local ready-mix quote; volume alone does not establish the cheaper option.
Is every 80 lb bag 0.60 cubic feet?
No. Use the yield printed on the sack. Bag size alone does not guarantee the same yield.
What is the formula ID?
This concrete bag calculator publishes formula CONC-BAG-001, version 1.0.0. The ID stays on the result and on the estimate line.