Concrete Estimator Hub
Concrete Volume Calculator for Yards, Bags, and Cost
Estimate concrete for rectangular slabs, triangle pads, footings, round holes, and columns. Get cubic yards, cubic feet, cubic meters, 40/60/80 lb bags, waste, cost, and the next buying check in one place.
Enter Measurements
Save this estimate or download a PDF report
The PDF report uses the current calculated result. Save the estimate first when you want to reuse the inputs later.
Results
Live estimateVolume buying decision in one screen
1.36 yd3 / 36.67 ft3 / 62 bags. Decision zone. Compare bagged material, store delivery, ready-mix minimums, and short-load fees.
Concrete yard calculator
Concrete yard calculator quick answer
For rectangular slabs, convert thickness from inches to feet, multiply length x width x thickness, then divide cubic feet by 27. For triangular slabs, use base x perpendicular height x thickness / 2 before dividing by 27.
V (yd3) = length (ft) x width (ft) x thickness (in) / 12 / 27V (yd3) = base (ft) x perpendicular height (ft) x thickness (in) / 12 / 2 / 27Current yardage
1.36 yd3
Current area
100 sq ft rectangular area
Bag fallback
62 bags
| Thickness | 1 yd3 covers | Planning use |
|---|---|---|
| 2 in | 162 sq ft | Thin overlay or non-structural topping check |
| 3 in | 108 sq ft | Light pad or walkway planning check |
| 4 in | 81 sq ft | Common patio, sidewalk, or shed-base estimate |
| 5 in | 64.8 sq ft | Driveway or heavier pad planning check |
| 6 in | 54 sq ft | Thicker slab, apron, or heavy-use pad check |
Coverage uses 324 divided by slab thickness in inches. Add waste after this quick check, then round the order with your supplier.
Metric concrete volume quick answer
For metric projects, use meters for length and width, convert thickness from centimeters to meters, then multiply. For a slab, use length m x width m x thickness cm / 100. A 10 m2 area at 10 cm thick is 1.0 m3 before waste.
Use cubic meters when talking to suppliers, then convert to bags only after checking the yield printed on the product. concrete bag calculator can help once you know whether the job is better handled with bags or delivered concrete.
| Shortcut | Use | Example |
|---|---|---|
| Area x thickness | Fast slab or pad estimate | 10 m2 x 10 cm = 1.0 m3 |
| Centimeters to meters | Divide thickness by 100 before multiplying | 8 cm = 0.08 m |
| Triangle area x thickness | Triangular pad or corner slab estimate | 0.5 x 6 m x 4 m x 10 cm = 1.2 m3 |
| Waste allowance | Add waste before converting to bags or ordering ready-mix | 1.0 m3 + 10% = 1.10 m3 |
Quick concrete answer
How much concrete do I need?
For the current measurements, plan on about 1.36 yd3 of concrete after waste. That is roughly 1.04 m3 and 62 bags before you choose a buying path.
Formula used
length x width x thickness, then add waste
Ordering buffer
Waste is already included. Confirm depth, subgrade, form leaks, spills, and supplier rounding before ordering.
Buying trigger
Comparison zone. Price bags, ready-mix minimums, delivery, and short-load fees side by side.
Do not stop at the volume number
The useful next step is to turn the quantity into a buying check: bags, concrete weight for hauling, local delivery, minimum loads, access fees, and quote scope.
Concrete calculator square feet
Square feet to concrete yards
When you know the slab area but not the yardage, use square feet and thickness first. The shortcut is square feet x thickness in / 12 / 27, while one cubic yard covers about 324 / thickness inches square feet before waste.
Current area
100 sq ft
9.29 m2
Coverage per yd3
81 sq ft
before waste
This estimate
1.358 yd3
62 bags
| Thickness | 1 yd3 covers | Yards with waste | bags |
|---|---|---|---|
| 2 in | 162 sq ft | 0.679 yd3 | 31 |
| 3 in | 108 sq ft | 1.0185 yd3 | 46 |
| 3.5 in | 92.57 sq ft | 1.1883 yd3 | 54 |
| 4 in | 81 sq ft | 1.358 yd3 | 62 |
| 5 in | 64.8 sq ft | 1.6975 yd3 | 77 |
| 6 in | 54 sq ft | 2.037 yd3 | 92 |
Bag yield: 0.6 ft3; Waste Factor: 10%
Measuring concrete in cubic meters for the Philippines?
Use the m3 result as the first number, then compare site-mixed bags, ready-mix delivery, pump access, VAT, rain timing, and supplier quote scope before ordering a Philippine carport, walkway, gate apron, or small slab.
Open the Philippines concrete planning pageWhat to do with the volume result
The cubic yard number is only the first decision. Use the result to choose a buying path, then check fees and access before you approve a supplier or contractor quote.
| Result range | Likely next step | Check before buying |
|---|---|---|
| Under 0.5 yd3 | Bagged concrete is usually practical | Confirm bag yield, mixing time, waste, and how many batches you can place before set time. |
| 0.5 to 2 yd3 | Compare bags with ready-mix delivery | Check minimum load, short-load fee, delivery charge, truck access, and helper availability. |
| Over 2 yd3 | Price ready-mix or review a contractor quote | Confirm PSI, slump, delivery window, chute reach, pump or buggy needs, and waiting-time rules. |
Formula
V (ft3) = length (ft) x width (ft) x thickness (in) / 12V (yd3) = area (ft2) x thickness (in) / 12 / 27V ≈ 10 ft x 10 ft x 0.333333 ft ≈ 33.333333 ft3Waste and bags
V_total ≈ 33.333333 ft3 x (1 + 10 / 100) ≈ 36.666667 ft3Bags = round up(36.666667 ft3 / 0.6 ft3) = 62Displayed quantities are rounded; whole bags use the unrounded volume. Bag yield depends on the product.
Method, units, and sources
Units and rounding
Thickness and diameter in inches are divided by 12; centimeters are divided by 100. 1 yd³ = 27 ft³. This calculator uses 1 ft³ ≈ 0.0283168 m³ and 1 m³ ≈ 35.3147 ft³. Volume results round to four decimal places; whole bags use the unrounded volume.
NIST SP 811: unit conversion referenceBag yield references
US presets match the approximate published yields for QUIKRETE Concrete Mix No. 1101: 40/50/60/80 lb → 0.30/0.375/0.45/0.60 ft³. Kg presets are planning approximations, not manufacturer specifications. Check your product label: bag weight alone does not establish yield.
QUIKRETE Concrete Mix No. 1101 data sheet (PDF)Allowance and ordering
The selected waste allowance (0–25%) is applied once before unit conversion and bag rounding. The 10% default is editable, not a required engineering factor. Results already include that allowance; confirm supplier order increments and minimum loads separately.
Maintained by Concrete Estimator Hub. Material planning only, not structural advice. Methods and corrections
Example Estimates
When To Use This Page
- Start here when you only know the shape and dimensions.
- Use it for broad cubic yard estimates before choosing bags or ready-mix.
- Move to a project-specific calculator when you need extra assumptions, such as stair landing volume or driveway waste.
Assumptions
- Rectangular mode assumes a flat, uniform-thickness pour.
- Triangle mode assumes a straight-sided triangular footprint with uniform thickness.
- Round mode assumes a solid cylinder with no voids.
- Bag yield and ready-mix ordering rules vary by product.
- This is a material estimator, not structural advice.