Calculator
Example data table
| Area | Depth | Waste | Volume (yd³) | Weight (lb) | 50 lb bags |
|---|---|---|---|---|---|
| 48 sq ft (12×4) | 2 in | 8% | 0.329 | 59 | 1.18 |
| 160 sq ft path | 3 in | 10% | 1.467 | 396 | 7.92 |
| Circle, 10 ft diameter | 4 in | 12% | 1.086 | 293 | 5.86 |
Examples assume 100 lb/ft³ density for simple planning.
Formula used
- Rectangle area = length × width
- Circle area = π × (diameter ÷ 2)²
- Triangle area = 0.5 × base × height
- Depth (ft) = inches ÷ 12, or cm ÷ 100 × 3.28084
- Volume (ft³) = area (sq ft) × depth (ft)
- Waste multiplier = 1 + (waste% ÷ 100)
- Volume with waste = volume × waste multiplier
- Volume (yd³) = volume (ft³) ÷ 27
- Weight (lb) = volume (ft³) × density (lb/ft³)
- Bags by weight = total weight ÷ bag weight
- Bags by volume = total volume ÷ bag volume
How to use this calculator
- Choose a unit system and the shape of your gravel area.
- Enter dimensions, or use Custom Area if already measured.
- Set the gravel depth and add a realistic waste percent.
- Confirm density and select how you want bags estimated.
- Optionally enter bag or bulk pricing plus delivery fees.
- Click Calculate to view results above the form.
- Download CSV or PDF to share and store estimates.
Pea Gravel Coverage Planning Guide
1) Understand coverage inputs
Coverage depends on surface area and installed depth. Area can be measured as rectangles, circles, triangles, or entered directly as a known value. Depth should reflect the compacted layer after raking and settling, not the loose pile height.
2) Typical depths for garden use
For light foot-traffic paths, a 2–3 inch layer is common. For high traffic or edging where stones migrate, 3–4 inches can improve stability. Thicker layers raise cost and can reduce drainage if fines accumulate over time.
3) Density drives weight and bag counts
Bulk density varies by quarry, moisture, and particle mix. Many pea gravel blends fall roughly near 90–110 lb/ft³. A higher density increases weight at the same volume, which changes the number of bags and the hauling effort.
4) Convert volume like a pro
This calculator converts depth to feet, then multiplies by area to get cubic feet. It also reports cubic yards because bulk gravel is often sold by the yard. One cubic yard equals 27 cubic feet, so small jobs can still be compared to bulk delivery pricing.
5) Add waste for settling and spillage
Waste accounts for compaction, leveling, and unavoidable losses. For tidy beds with edging, 5–10% is usually reasonable. For uneven ground, curves, or first-time installs, 10–15% helps avoid under-ordering and patchy coverage.
6) Bags versus bulk delivery
Bagged gravel is convenient for small projects and tight access, but it often costs more per unit volume. Bulk delivery becomes cost-effective as volume increases, especially once you include time savings. Use the bag and yard pricing fields to compare both options.
7) Keep results realistic
For metric entries, the calculator converts m² to sq ft, centimeters to inches, and kg/m³ to lb/ft³ so all outputs stay consistent. If your supplier sells by the tonne or cubic meter, use the provided metric weight and m³ values for ordering.
8) Field tips that reduce rework
Install landscape fabric only where needed, and pin edges so gravel does not mix with soil. Use edging to hold depth, and lightly compact or water-settle to reveal the true finished height. Recheck low spots before ordering the final top-up.
FAQs
1) How much pea gravel covers 100 square feet?
At 2 inches deep, 100 sq ft needs about 0.62 yd³ (around 16.7 ft³). Add 5–10% waste for settling and leveling to avoid coming up short.
2) What depth is best for a garden path?
Many paths work well at 2–3 inches after leveling. Choose 3–4 inches for higher traffic, softer subgrade, or where stones tend to kick out.
3) Should I include a waste percentage?
Yes. Waste covers compaction, grading, and minor spillage. Use 5–10% for simple rectangles with edging, and 10–15% for curves, uneven terrain, or first-time installs.
4) Why do my bag estimates vary from the store labels?
Bag counts depend on actual bag weight or volume, plus material density and moisture. Use your bag’s printed weight or volume, and keep density near your supplier’s typical range for better accuracy.
5) Is bulk delivery cheaper than bags?
Often yes for medium and large projects. Bulk pricing per yard is usually lower, and you reduce handling time. Bags can still win when access is limited or the required volume is very small.
6) Can I use this for metric ordering?
Yes. Enter m² and cm, and use kg/m³ for density. The results include cubic meters and tonnes, which are helpful when suppliers quote by m³ or by the tonne.
7) What if my area is irregular?
Break the space into simple shapes, calculate each area, and add them together. If you already know total area from a plan, select Custom Area and enter that value directly.