Reviewed · Prices checked October 2026 · How we calculate

Compost Calculator: How Much for Beds and Lawns

Enter the size of your lawn or bed and pick the job. You get the bags to buy, or the cubic yards to order in bulk, and what it costs at your store's price.

Area and depth

Units
Job

Sets the depth below. You can type any depth instead.

Shape
ft
ft
in

¼ in to top-dress a lawn, 1 to 3 in worked into a bed.

    Buy as

    Shopping list

    Updates as you type
    34bags

    of 1 cu ft compost (33.3 cu ft (1.23 cu yd) needed)

    Same job: 34 bags of 1 cu ft, or 1.5 cu yd bulk.

    • 34 × 1 cu ft bags of compost$102–$340
      33.3 cu ft ÷ 1 cu ft per bag = 33.3, rounded up.

      Typical price (estimate, checked Oct 2026): $3.00–$10.00 per 1 cu ft bag of compost

      34 bags × $3.00–$10.00 = $102–$340Estimate
    Project total (estimate where no price is entered)$102–$340
    Checked Oct 2026
    Show the math
    Area: 10 × 20 ft = 200 sq ft200 sq ft × 2 in ÷ 12 = 33.3 cu ft = 1.23 cu yd33.3 cu ft ÷ 1 cu ft per bag = 33.3 → 34 bags

    Your prices are saved on this device only.

    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.

    34 bags of 1 cu ft$102–$340
    1.5 cu yd bulk, delivered$80–$225

    Prices used in this comparison

    Typical price (estimate, checked Oct 2026): $3.00–$10.00 per 1 cu ft bag of compost

    Typical price (estimate, checked Oct 2026): $20.00–$50.00 per cu yd of compost

    Typical price (estimate, checked Oct 2026): $50.00–$150.00 per delivery

    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

    cu ft = L (ft) × W (ft) × depth (in) ÷ 12
    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

    1. 10 × 20 × 2 ÷ 12 = 33.3 cu ft
    2. In yards: 33.3 ÷ 27 = 1.23 cu yd
    3. In 1 cu ft bags: 33.3 ÷ 1 = 33.3, round up to 34 bags
    4. In bulk: 1.23 cu yd rounds up to 1.5 cu yd
    5. Bags at $6.50 (the middle of our typical range): 34 × $6.50 = $221
    6. Bulk at $35.00 a yard: 1.5 × $35.00 = $52.50, plus one $100 delivery = $152.50

    What a cubic yard covers

    Square feet that one cubic yard of compost covers at each depth
    Depth¼ in½ in1 in2 in3 in
    Sq ft per cu yd1,296648324162108

    Common sizes

    Compost needed for common beds and a lawn
    AreaDepthCu ftCu yd1 cu ft bagsBulk order
    Bed 4 × 8 ft2 in5.30.2060.5 cu yd
    Bed 10 × 10 ft2 in16.70.62171 cu yd
    Bed 10 × 20 ft2 in33.31.23341.5 cu yd
    New bed 10 × 20 ft3 in50.01.85502 cu yd
    Lawn 25 × 40 ft (1,000 sq ft)¼ in20.80.77211 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.