Bagged vs bulk
Bulk is cheaper for this job
With these prices and $100 delivery, bulk starts to win at about 0.8 cu yd (about 122 sq ft at 2 in). Bulk cost rises in half-yard steps.
Prices used in this comparison
Typical price (estimate, checked Oct 2026): $3.00–$10.00 per 1 cu ft bag of compost
Use a price like 3.00.
Typical price (estimate, checked Oct 2026): $20.00–$50.00 per cu yd of compost
Use a price like 20.00.
Typical price (estimate, checked Oct 2026): $50.00–$150.00 per delivery
Use a price like 50.00.
1.5 cu yd × $20.00–$50.00 + $50.00–$150.00 delivery = $80–$225
Delivery is one fee for the bulk order, and it carries over to the gravel, mulch and topsoil calculators. Bags are priced per 1 cu ft bag. Bulk uses the per cu yd price.
How it works
The formula
bags = cu ft ÷ 1, round up
cu yd = cu ft ÷ 27, round up to 0.5
Assumptions
- Depth presets: top-dress a lawn ¼ in, mix into a garden bed 2 in, new bed or amend heavily 3 in. University extension guidance for lawns is about ¼ in of compost, up to ½ in, raked into the grass. For beds it is usually 1 to 3 in worked into the top 6 to 8 in of soil. The exact presets are a rule of thumb.
- Bags are counted by the volume printed on the bag. We use 1 cu ft, the most common size. Check the label, because some bags hold 0.75 or 1.5 cu ft.
- Bulk compost is sold by the cubic yard, so we round up to the next 0.5 yard.
- A cubic yard is 27 cu ft, which is 27 bags of 1 cu ft.
- No extra is added. Compost settles a little, so add a bag or two for uneven ground.
Worked example
A 10 × 20 ft bed, compost mixed in 2 in deep
- 10 × 20 × 2 ÷ 12 = 33.3 cu ft
- In yards: 33.3 ÷ 27 = 1.23 cu yd
- In 1 cu ft bags: 33.3 ÷ 1 = 33.3, round up to 34 bags
- In bulk: 1.23 cu yd rounds up to 1.5 cu yd
- Bags at $6.50 (the middle of our typical range): 34 × $6.50 = $221
- Bulk at $35.00 a yard: 1.5 × $35.00 = $52.50, plus one $100 delivery = $152.50
What a cubic yard covers
| Depth | ¼ in | ½ in | 1 in | 2 in | 3 in |
|---|---|---|---|---|---|
| Sq ft per cu yd | 1,296 | 648 | 324 | 162 | 108 |
Common sizes
| Area | Depth | Cu ft | Cu yd | 1 cu ft bags | Bulk order |
|---|---|---|---|---|---|
| Bed 4 × 8 ft | 2 in | 5.3 | 0.20 | 6 | 0.5 cu yd |
| Bed 10 × 10 ft | 2 in | 16.7 | 0.62 | 17 | 1 cu yd |
| Bed 10 × 20 ft | 2 in | 33.3 | 1.23 | 34 | 1.5 cu yd |
| New bed 10 × 20 ft | 3 in | 50.0 | 1.85 | 50 | 2 cu yd |
| Lawn 25 × 40 ft (1,000 sq ft) | ¼ in | 20.8 | 0.77 | 21 | 1 cu yd |
Bag counts are rounded up; bulk is rounded up to the half yard.
Questions people ask
How much compost per square foot?
It depends on the depth. At 2 in, each square foot takes 0.17 cu ft, so a 100 sq ft bed takes 17 bags of 1 cu ft. At 1 in it is half that, and at 3 in it is 25 bags for the same 100 sq ft.
How much compost do I need to top-dress a lawn?
Spread about ¼ in, and no more than ½ in, so the grass can grow through it. A 1,000 sq ft lawn at ¼ in takes 20.8 cu ft, which is 0.77 cu yd. That is 21 bags, or 1 cu yd in bulk.
How many bags of compost are in a yard?
27 bags of 1 cu ft. A cubic yard is 27 cu ft. One yard covers about 1,296 sq ft at ¼ in, 324 sq ft at 1 in, or 162 sq ft at 2 in.
What is the difference between compost and topsoil?
Compost is decomposed organic matter that feeds soil and improves its structure. Topsoil is mineral soil that gives plants something to root in. Compost is usually mixed into the soil you have, or into topsoil, rather than used alone. Use the topsoil calculator if you need to fill or level.
When should I add compost?
Spring and fall are the best times. Work it into beds before planting, or spread it on the lawn in fall or early spring while the grass is growing. You can also add a thin layer around established plants at any time of the growing season.