3 4 Rock Calculator

Instantly calculate cubic yards, tons and cubic feet for any rock fill project – free and instant.

  • Free
  • No sign-up
  • Instant results

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How to use it

  1. Enter length in feet
  2. Enter width in feet
  3. Enter depth in inches
  4. Read cubic yards, tons and cubic feet results

What it does – You enter length, width and depth of the rock area and the tool returns three numbers: total cubic feet, cubic yards and an approximate tonnage (1 yard = 1.4 US tons). Why it matters – Knowing volume helps you order the right amount of material, avoid over‑paying for excess and plan site logistics. How to read – Cubic feet is the raw volume, divide by 27 to get cubic yards, then multiply by 1.4 to see the weight in tons. Use the ton figure when requesting quotes from suppliers; most quote by the ton. Most projects add a 5‑10% waste factor to cover breakage and compaction. If your depth is given in inches, the calculator converts it to feet automatically, so you don’t need to do the math yourself. The result is displayed instantly, letting you compare quotes side‑by‑side. Remember that the ton estimate is approximate; supplier densities can vary slightly, but 1.4 tons per cubic yard is the industry standard for loose rock.

Pro tips

  • Add 5‑10% extra for breakage and compaction
  • Round up to the nearest whole yard for ordering
  • Check supplier density specs; 1.4 tons/yd³ is a baseline
  • Enter depth in inches; the tool handles conversion

Real-life examples

  • A homeowner planning a new patio needs to know how much rock base to order
  • A landscaper estimating material for a garden retaining wall
  • A contractor quoting a client for a driveway sub‑base

Case study

Jane entered her 12 ft × 8 ft area with a 4‑inch depth, got 11.3 cubic yards and 15.8 tons, ordered 12 yards, and avoided a costly shortage, finishing her patio on schedule.

Frequently asked questions

How do I convert my depth from inches to feet?
Just type the depth in inches; the calculator does the conversion automatically.
Why is the tonnage only an approximation?
Because rock density can vary; 1.4 tons per cubic yard is the standard estimate for loose rock.
Should I order more than the calculated volume?
Yes, add a 5‑10% waste allowance to cover breakage and compaction.
What if my area isn’t a perfect rectangle?
Break the space into rectangles, calculate each, then add the results.
Do I need to create an account to use the calculator?
No, it’s free and requires no sign‑up.