Enter Project Details
Example Data Table
| Item | Example Value | Notes |
|---|---|---|
| Area | 1,200 sq ft | Typical medium garden path and border project. |
| Depth | 2.5 inches | Common decorative gravel depth. |
| Crew Size | 3 workers | Balanced crew for spreading and leveling. |
| Base Production | 180 sq ft/hr/worker | Before depth and site adjustments. |
| Hourly Wage | $22 | Base pay before burden and overtime. |
| Equipment Cost | $120 | Plate compactor, wheelbarrows, or hand tools. |
| Overhead + Profit | 12% + 10% | Applied after labor, equipment, and misc costs. |
Formula Used
This calculator uses a productivity-based estimating method. It converts area and depth, adjusts worker output for site conditions, then builds a full labor price.
1) Gravel Volume
Volume (cu ft) = Area (sq ft) × Depth (in) ÷ 12 Volume (cu yd) = Volume (cu ft) ÷ 27 Volume with Waste = Volume (cu yd) × (1 + Waste %)2) Adjusted Productivity
Adjusted Production = Base Production × Depth Factor × Surface Factor × Access Factor × Slope Factor × Pass Factor3) Labor Time
Spreading Hours = Area (sq ft) ÷ Crew Production Elapsed Job Hours = Spreading Hours + Prep + Cleanup + Travel Total Labor Hours = Elapsed Job Hours × Crew Size4) Cost Build-Up
Direct Labor = Regular Hours × Wage + Overtime Hours × Wage × Multiplier Labor Subtotal = Direct Labor + Labor Burden Grand Total = (Labor + Equipment + Misc + Overhead) + ProfitBecause labor productivity changes sharply with depth, access, and slope, this estimate is best used for planning, quoting, and crew scheduling.
How to Use This Calculator
- Enter the total gravel coverage area and choose the matching unit.
- Enter the target spread depth in inches or centimeters.
- Set the crew size and the expected base production per worker.
- Add prep, cleanup, and travel hours for a realistic field estimate.
- Enter wage, burden, overhead, profit, and any equipment or misc costs.
- Choose surface, access, slope, and compaction settings to reflect site difficulty.
- Click the calculate button to show the result above the form.
- Use the CSV or PDF buttons to export the final estimate.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates labor hours, labor cost, overhead, profit, and total project price for spreading gravel in garden paths, beds, borders, and open landscape areas.
2) Why does gravel depth affect labor time?
Deeper gravel means more material to move, level, and compact. That reduces worker coverage per hour and increases both elapsed job time and total crew hours.
3) What is base production per worker?
It is the expected area one worker can spread in an hour under standard conditions. The calculator then adjusts that rate for access, slope, depth, and site difficulty.
4) Should I include waste allowance?
Yes. Waste allowance helps cover spillage, uneven subgrade, edge loss, and small overfills. It improves planning accuracy, especially on irregular or decorative garden layouts.
5) Does this include gravel material price?
No. This version focuses on labor-related estimating, plus equipment, misc costs, overhead, and profit. Material purchase and delivery can be added separately if needed.
6) How is overtime handled?
The calculator compares total labor hours with the regular hour limit per worker. Any extra hours are priced using the overtime multiplier you enter.
7) Why are access and slope included?
Restricted access and sloped ground slow down hauling, raking, leveling, and compaction. These factors reduce effective productivity and make the estimate more realistic.
8) Is this suitable for quoting clients?
Yes, for preliminary and internal quoting. It is especially useful when comparing crew sizes, wages, and productivity assumptions before creating a final garden project proposal.