| Metric | Value | Copy |
|---|---|---|
| {{ row.label }} | {{ row.display }} |
| Decision Metric | Estimate | Copy |
|---|---|---|
| {{ row.label }} | {{ row.display }} |
Enter bed dimensions and a target depth to turn a footprint into an orderable soil quantity.
Open Advanced when you want top-up credits, bag-vs-bulk math, weight, or truck guidance.
Soil ordering gets confusing fast because the quantity you measure in the yard is rarely the quantity a supplier sells. Garden notes are usually written in feet, inches, or meters, while delivery tickets are written in cubic yards or cubic meters. If you are topping up an older bed, the wall height can be misleading too because part of that space may already be filled.
This calculator turns that into a practical order target. It works with rectangular beds, circular beds, and irregular areas entered directly as surface area. It converts between imperial and metric units, multiplies by bed count, subtracts any existing soil depth you already have, and then adds a separate allowance for settling, grading loss, or simple caution.
The result is more than one headline number. The page shows coverage area, full target volume before credits, existing soil credit, net fill before allowance, allowance add-on, final order target, and loose-volume checks. A second planning view translates the same quantity into a selected bag plan, a rounded bulk ticket, wheelbarrow trips, estimated truck loads, and a delivery-weight estimate.
Advanced fields let you move from geometry into logistics. You can choose a soil profile, override density, set a wheelbarrow capacity, compare a selected bag size against a bulk quote, account for a delivery minimum and order increment, and export totals as CSV, DOCX, chart images, or JSON. All calculations and exports stay on your device, so the copied and downloaded outputs come from the same visible state on the page.
The calculation normalizes everyday inputs into one internal unit system before anything is compared or exported. Lengths and depths are converted to meters, surface area to square meters, volume to cubic meters, and density to kilograms per cubic meter. That lets the tool keep one stable geometry model while still reporting cubic yards, cubic feet, liters, pounds, kilograms, tonnes, and short tons where they are useful.
| Input or setting | What it changes | What it does not change |
|---|---|---|
| Shape, dimensions or direct area, Target soil depth, and Bed count | Coverage area, full target volume, net fill, allowance volume, and final order target | The density-based weight estimate and the bag or bulk pricing rules until a quantity exists |
| Existing soil depth | Existing soil credit and the reduced top-up volume that still has to be ordered | The original footprint or the chosen target depth |
| Extra allowance | Allowance add-on and final order target | Coverage area, full target volume before credits, or existing soil credit |
| Soil profile and Bulk density | Estimated delivery weight and per-bag lift weight when a bag plan exists | The cubic quantity that must be filled |
| Selected bag size, Bag price, Bulk quote price, Bulk minimum order, Bulk order increment, and Truck capacity | Bag count, bagged cost, rounded bulk ticket, bulk cost, and truck-load estimate | The exact net fill that comes from the geometry |
| Wheelbarrow capacity | Wheelbarrow trip estimate and the optional handling line on the chart | Final order target, bag count, or bulk ticket size |
The chart uses the same staged calculation you see in the tables. The bars walk through Target fill, Existing credit, Net fill, Allowance, Final order, and Rounded bulk. If bag math or wheelbarrow math is active, a second line shows how those same stages translate into bag counts or hand-move loads.
The page also protects against misleading entries. Required dimensions and target depth must be above zero, bed count is rounded to a whole bed, allowance is clamped to 0 to 40 percent, and negative logistics inputs are reset to zero. If the existing depth already meets or exceeds the target, the final order target falls to zero and the recommendation flips to a no-extra-soil state.
Start by matching the input shape to the way you actually measured the site. Use a rectangle when you have a clean inside length and width, a circle when the bed is truly round, and direct area when the footprint already came from a sketch, survey, or plan. That last option is especially useful for curved borders or reclaimed planters where rebuilding the shape would add guesswork instead of removing it.
Depth deserves more thought than most people give it. For raised beds built over a hard surface, University of Maryland Extension recommends at least 8 inches for leafy greens, beans, and cucumbers, and roughly 12 to 24 inches for peppers, tomatoes, and squash. This calculator does not choose that depth for you, but it gives you a clean way to compare what each depth choice means for the order volume before you buy anything.
The calculator works best as an ordering worksheet rather than a soil-recipe advisor. It tells you how much material must arrive and how that volume translates into handling choices. It does not decide whether you should buy topsoil, raised-bed mix, compost-rich blend, or another medium. That choice still depends on what you are planting and what your supplier is actually selling.
Read the totals in order rather than jumping straight to the final number. The sequence shows where the order size came from and makes it easier to explain the quote to someone else. That matters when a supplier, contractor, or family member wants to know why the purchase is larger than the bare footprint-times-depth number.
| Output | What it means | Why it matters |
|---|---|---|
| Coverage area | The actual footprint being filled or topped up | This is the fastest way to catch a bad measurement before it distorts every later number. |
| Full target volume before credits | The total volume the bed would need if it were empty | Useful for new builds or for checking whether an existing-soil credit is too aggressive. |
| Existing soil credit | The portion already present, capped so it cannot exceed the target depth | This is the key top-up field. It stops you from paying twice for soil already in place. |
| Net fill before allowance | The exact geometric quantity still missing after the credit is removed | This is the clean comparison number for supplier quotes before any safety buffer is added. |
| Allowance add-on | The extra volume introduced by the allowance slider | It shows how much of the final order is risk buffer rather than strict geometry. |
| Final order target | The quantity you should order after the net fill and allowance are combined | This is the headline number used for the bag plan, bulk ticket, and handling estimates. |
The delivery rows answer a different question from the geometry rows. Selected bag plan tells you how many whole bags are needed at the chosen bag size, Rounded bulk ticket shows what the supplier billing rule does to the exact need, Wheelbarrow trips translates the job into hand-move effort, and Estimated delivery weight turns the same final volume into a loading estimate.
| Recommendation state | When it appears | How to read it |
|---|---|---|
| No extra soil | Existing depth already meets or exceeds the target depth | The bed already has enough depth, so the order target falls to zero. |
| Bag pickup | The selected bag plan is 12 bags or fewer and the exact bulk need stays below the delivery minimum | A small run where bag pickup is often simpler than forcing a delivery ticket. |
| Bags favored | Bag and bulk prices are both entered, the bagged total is cheaper, and the bag plan is 24 bags or fewer | A price-based nudge toward bags when the count is still manageable. |
| Bulk delivery | The bag plan reaches 20 bags or more, or the exact bulk need reaches at least the larger of the minimum order or 1.5 bulk units | A quantity-based nudge toward bulk even when no prices are entered. |
| Bulk favored | Bag and bulk prices are both entered and the bulk total is cheaper | A price-based push toward the rounded bulk ticket. |
| Compare both | No stronger rule above is triggered | The job sits in the crossover zone, so local convenience matters as much as the math. |
Treat the weight line as an estimate rather than a shipping guarantee. USDA NRCS guidance notes that bulk density changes with texture and compaction, and wet soil is more vulnerable to density shifts than dry soil. In practice that means a fluffy raised-bed mix and a wet screened topsoil can share the same cubic quantity but produce very different lifting and trailer loads.
Use the default rectangular example: one bed, 8 ft long, 4 ft wide, and 6 in deep, with a 10 percent allowance. The footprint is 32 sq ft. Because the bed starts empty, the full target volume before credits is 16 cu ft and the existing soil credit is zero.
After the 10 percent allowance, the final order target becomes 17.6 cu ft, which is about 0.65 cu yd or 0.498 m³. If the selected bag size is 2 cu ft, the tool rounds to 9 bags. If a wheelbarrow holds 6 cu ft, the same job becomes about 2.9 loads. With a density of 80 lb/ft³, the estimated delivery weight is about 1,408 lb.
This is a good example of how the page separates exact need from buying friction. The exact order target is smaller than a full cubic yard, but a supplier with a 1 cu yd minimum will still bill the rounded bulk ticket at 1.0 cu yd.
Suppose an irregular planter already has a measured area of 14 m². You want a final depth of 15 cm, there is already 5 cm of soil in place, and you add a 10 percent allowance. The full target volume before credits is 2.1 m³. The existing soil credit is 0.7 m³, so the net fill before allowance is 1.4 m³.
After the allowance, the final order target becomes 1.54 m³, which is about 2.01 cu yd. If the selected bag size is 50 L, the job rounds to 31 bags. If the supplier has a 1 m³ minimum order and sells in 0.5 m³ steps, the rounded bulk ticket becomes 2.0 m³. At 1,280 kg/m³, the estimated delivery weight is about 1,971 kg.
This is the kind of run where the recommendation usually leans toward bulk even before price is entered. The exact fill is already well above a token delivery size, and the bag count is high enough that hand-moving store bags becomes its own project.
Yes. Enter the soil already present in Existing soil depth. The tool converts that to an existing soil credit and subtracts it from the full target volume before allowance is added.
Yes. Changing the measurement system converts the current entries so you can compare cubic yards and cubic meters without retyping the form.
Because suppliers rarely bill the exact geometric number. The page applies the entered minimum order and the delivery increment, then rounds up to a sellable bulk ticket.
The top-up depth falls to zero, the final order target becomes zero, and the recommendation changes to a no-extra-soil state. The existing credit is capped so it cannot exceed the target depth.
Because weight depends on density, not just volume. A dry, light raised-bed mix and a wet, compacted topsoil can have the same cubic quantity but very different total weights and bag-lift loads.
Yes. A common garden conversion is 1 cubic yard = 27 cubic feet. For simple rectangular beds you can often sanity-check the volume as length × width × depth in feet, then divide by 27 to get cubic yards before considering any existing-soil credit or allowance.
Yes. The page can copy or download CSV totals, export DOCX summaries, save chart images and chart CSV data, and copy or download a full JSON record of the current run. Those exports are generated locally from the current calculator state.