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Fifteen of them, grouped the way a job is quoted. The ones you opened last sit at the top under Recent.
Trademath for Android
Cubic yard calculator
For the people who buy the material. Put in the slab and get what you actually order at the yard: cubic yards of ready-mix, how many 80-lb bags, and what each option costs at your own prices.
Free · Offline · No account · No ads
Get it on Google PlayListed on Google Play as Cubic Yard Calculator.
How many cubic yards of concrete do I need?
Multiply length by width by thickness, all in feet, then divide by 27. A 4-inch slab is 0.333 ft thick, 5 inches is 0.417 ft, 6 inches is 0.5 ft.
length × width × thickness (ft) ÷ 27 = cubic yards
A 10 by 10 foot slab at 4 inches is 100 × 0.333 = 33.3 cubic feet, which is 33.3 / 27 = 1.23 cubic yards. Order a little over: most crews add 5 to 10 percent for spillage and uneven subgrade.
Concrete slab yardage
| Slab | 4 in (cu yd) | 6 in (cu yd) | 80-lb bags at 4 in |
|---|---|---|---|
| 10 × 10 ft | 1.23 | 1.85 | 56 |
| 12 × 12 ft | 1.78 | 2.67 | 80 |
| 20 × 20 ft | 4.94 | 7.41 | 223 |
| 24 × 24 ft | 7.11 | 10.67 | 320 |
Bag counts assume an 80-lb bag of concrete mix yields 0.60 cubic feet.
Or skip the arithmetic
Type the slab the way you measured it — 24′ × 12′ 6″ × 4″, fractions and all — and the app carries the waste allowance and your supplier's prices through to the number you give the yard. The formulas are cross-checked against ACI E1-16 and published QUIKRETE product data; the sources are listed inside the app.
Get it on Google PlayHow it works
Three screens between a tape measure and an order.
Type it the way you measured it
Feet, inches and fractions — 12′ 6 1/2″ — with 1/2, 1/4, 1/8 and 1/16 on the keypad. Waste is a field, not something you add in your head afterwards.
Order the right amount
Net, waste and order quantity on separate lines, then what each way of buying it costs at your own supplier prices.
Fifteen calculators
Every one that ends in a purchase shows the waste allowance on its own line, so the job quantity and the order quantity never get mixed up.
Concrete
- Concrete Slab
- Round Slab
- Footing
- Column / Pier
- Stairs
- Post Holes
Aggregate
- Gravel
- Sand
- Mulch
- Asphalt
Area & Lumber
- Square Footage
- Perimeter
- Board Feet
Paint
- Paint — Walls
- Paint — Ceiling
In the app
Swipe through. Nothing here is a mockup.
Your prices, your totals
Enter what your yard charges. Nothing ships with the app and nothing is downloaded.
One project per job site
Calculations add up by material and give you a single total for the job.
Hand the client an estimate
Export a project as a PDF or as plain text and send it from the phone.
Openings come off the wall
Doors and windows are deducted before it figures the gallons.
Readable in direct sun
One tap makes the figures bigger and the contrast higher.
Reference
Bags per cubic yard
| Bag | Yield | Bags per cu yd |
|---|---|---|
| 80 lb | 0.60 cu ft | 45 |
| 60 lb | 0.45 cu ft | 60 |
| 40 lb | 0.30 cu ft | 90 |
A cubic yard is 27 cubic feet. Past about a cubic yard, ready-mix is usually cheaper and always less work than mixing bags.
Mulch coverage, one cubic yard
| Depth | Covers |
|---|---|
| 2 in | 162 sq ft |
| 3 in | 108 sq ft |
| 4 in | 81 sq ft |
Gravel and stone are sold both ways. Crushed stone runs around 1.4 tons per cubic yard, but density varies by material and moisture — ask your supplier for theirs before converting.
These figures are reference estimates. Confirm quantities with your supplier before ordering, and follow local building code.
Questions
How many cubic yards is a 10 by 10 slab at 4 inches?
1.23 cubic yards. Length times width times thickness, all in feet, divided by 27: 10 × 10 × 0.333 = 33.3 cubic feet, and 33.3 / 27 = 1.23. Most crews order 5 to 10 percent over for spillage and uneven subgrade.
How many 80-lb bags of concrete make a cubic yard?
About 45. An 80-lb bag of concrete mix yields roughly 0.60 cubic feet and a cubic yard is 27 cubic feet. A 60-lb bag yields about 0.45, so 60 bags; a 40-lb bag about 0.30, so 90 bags. Past about a cubic yard, ready-mix is usually cheaper and always less work.
How many cubic yards is a ton of gravel?
Crushed stone runs around 1.4 tons per cubic yard, so a ton is roughly 0.7 cubic yards. Density varies by material and moisture — ask your supplier for theirs before converting.
How much mulch do I need?
One cubic yard covers about 108 square feet at 3 inches deep, 162 square feet at 2 inches, or 81 square feet at 4 inches.
Is it free, and does it work without a connection?
Yes to both. No ads, no in-app purchases, no account. The app requests no Android permissions at all — it has no internet permission — so every measurement and price stays on the phone.
Put it on the truck
Free, no ads, no account. It asks for no Android permissions at all — not even internet — so your measurements and your prices stay on the phone.
Get it on Google Play