Miracle-Gro Garden Soil Calculator
Calculate soil bags and costs for in-ground beds, with bag-size and store-brand comparisons.
Calculator Inputs
For in-ground soil amendment. Mix the layer into native soil; use a suitable growing medium for pots or raised-bed fill. Prices start from illustrative USD references; enter your local shelf prices. Converted estimates are not local supplier quotes.
Bag Size Comparison
| Bag Size | Price Basis | Estimated Total Cost |
|---|---|---|
| 0.75 cu ft bag | $4.57/bag ($6.09/cu ft) | - |
| 1.5 cu ft bag | $8.47/bag ($5.65/cu ft) | - |
Application Depth Comparison
| Depth | Volume Needed | Estimated Cost |
|---|---|---|
| 2 in depth | - | - |
| 3 in depth | - | - |
Calculation Breakdown
| Step | Calculation | Result |
|---|---|---|
| Bed area | Enter your bed's shape and size above | - |
| Volume needed | - | - |
| Bags needed | - | - |
| Miracle-Gro cost | - | - |
| Exact-volume allowance | - | - |
| Cost difference | - | - |
What Is Miracle-Gro Garden Soil For?
Scotts Miracle-Gro describes Garden Soil All Purpose as an amendment for outdoor in-ground planting. Spread 2–3 inches over existing soil and mix it into the top 6–8 inches of native soil. The manufacturer states that it feeds plants for up to 3 months; this calculator does not measure that benefit.
Garden soil is not the same as potting mix. Do not use this estimate as an instruction to fill a pot or a raised bed with this product alone. Follow the label on your exact bag and choose a growing medium intended for your planting situation.
How This Calculator Works Out Your Bag Count
Multiply area in square feet by application depth in inches, then divide by 12 to get cubic feet. For an 8 × 4 ft bed at 2 inches, 32 × 2 ÷ 12 = 5.33 cu ft. Divide by the 1.5 cu ft bag size and round up: 4 bags, buying 6 cu ft. At the illustrative USD 8.47 per bag, the cost is USD 33.88.
The manufacturer’s coverage example uses two 2 cu ft bags for 24 sq ft at 2 inches, consistent with this volume formula. Measure the amendment layer you intend to add, rather than the entire depth of native soil you will mix it into.
Comparing A Whole-Bag Order With An Allowance
The comparison rate starts at an illustrative USD 4.35 per cu ft. The default job therefore has an exact-volume allowance of 5.3333 × 4.35 = USD 23.20, against USD 33.88 for the branded whole-bag order: a USD 10.68 difference, or 46% of the allowance.
This is not a like-for-like checkout quote: the allowance excludes rounding up the alternative’s bags. Some of the difference pays for leftover soil, not the brand. Enter a comparison unit rate from a suitable product at your store; its actual order may cost more once bag sizes, delivery and tax are included. A zero rate disables the percentage comparison.
Choosing Between The 0.75 And 1.5 Cu Ft Bags
The 0.75 cu ft and 1.5 cu ft Home Depot listings identify the bag sizes used here. USD 4.57 and USD 8.47 are illustrative reference prices used for these examples, not confirmed current local offers. Their unit costs are USD 6.09 and USD 5.65 per cu ft.
Your edited price applies to the selected size in the dashboard, scenarios and advice. The other size uses its labelled reference price. For the default bed, the smaller bags cost 8 × USD 4.57 = USD 36.56. If the selected larger bag costs USD 20, its 4-bag total becomes USD 80, making the smaller reference order cheaper. Confirm both prices before buying.
Rounding can reverse a unit-price advantage. A 2 sq ft in-ground patch at 3 inches needs 0.5 cu ft, so either size requires just 1 bag. At the reference prices, the smaller bag costs USD 4.57 versus USD 8.47 for the larger bag. Keep usable leftovers for another appropriate in-ground job.
Method and limits
Area is length × width for a rectangle, π × (diameter ÷ 2)² for a circle, or your entered area. Volume is area × depth ÷ 12. Each scenario rounds volume divided by bag capacity up to a whole bag; cost is bag count × bag price. Percent difference is (order cost − comparison allowance) ÷ allowance × 100, only when the allowance is positive. Display rounding happens after calculation.
- Assumes a flat prepared bed. Uneven ground, settling, compaction and existing amendments can change the amount you need; no extra wastage percentage is added.
- Excludes sales tax, delivery and bulk-soil quotes. A cubic yard is 27 cu ft, but whether bulk delivery is cheaper depends on your actual supplier and delivery charge.
- USD references are examples, not a live price feed. Currency conversion changes money only: feet, inches and cubic feet remain unchanged. It does not establish availability or a local supplier quote.
- Custom depths from 0.5 to 24 inches show volume arithmetic. Depths outside the manufacturer’s 2–3 inch range trigger a scope reminder, not a recommendation to use that depth.
Method and manufacturer guidance reviewed . Confirm local prices and follow your product label.
Frequently Asked Questions
Can I use this for a raised bed or a pot?
The volume arithmetic can describe any shape, but this product is intended to amend in-ground soil. It is not a standalone growing medium for a pot or raised-bed fill. Choose a mix labelled for that use and follow its directions.
Is Miracle-Gro worth the extra cost?
The tool compares material quantities and prices, not growing performance. The default USD 10.68 difference includes whole-bag rounding on the branded order but not on the comparison allowance. Consider the actual alternative bag cost and suitability before deciding.
Why can the smaller bag be cheaper despite a higher unit price?
For 0.5 cu ft of amendment, either bag size requires one bag. At the illustrative references that means USD 4.57 for the smaller bag or USD 8.47 for the larger one. Compare the whole order and whether you can use the extra soil.
Is this an official Home Depot or Miracle-Gro calculator?
No. CoryVu provides this independent calculator. It is not affiliated with or endorsed by The Home Depot or Scotts Miracle-Gro.
How do I enter a store-brand price per cubic foot?
Divide the alternative bag price by its cubic feet. For example, a USD 9 bag containing 2 cu ft gives USD 4.50 per cu ft. Enter that rate in the comparison field, using your selected currency. The resulting allowance still excludes rounding up the alternative’s bags.
Sources
- Scotts Miracle-Gro — product use and coverage guidance
- The Home Depot — Miracle-Gro Garden Soil All Purpose, 0.75 cu ft
- The Home Depot — Miracle-Gro Garden Soil All Purpose, 1.5 cu ft
- Lowe's — Sta-Green Garden Soil (store-brand comparison)
Last updated: 2026-09-23. This page gives a materials and cost estimate only. It is not a professional quote and is not affiliated with, endorsed by, or a product of The Home Depot or Scotts Miracle-Gro.
About this tool
Created and maintained by CoryVu. Read how we check our tools and consult the sources and assumptions on this page.
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