Lawns · garden beds · low spots

Topsoil Calculator

Plan the new soil layer your project needs. Combine different areas and depths, exclude paths or obstacles, then estimate loose topsoil, whole bags, bulk ordering quantity, and material plus delivery cost.

Calculate Topsoil How to Measure

Worked example

12 × 9 ft · 3 in added depth1 cu yd

With 20% settling volume loss: 1.25 loose cu yd
Plus 10% extra allowance: 1.375 cu yd target
Using 0.75 cu ft bags: 50 whole bags

Example only. Depth and settling are not recommendations or prefilled values.

Your measurements

Plan your topsoil layer

Combine sections for one material. Include only non-overlapping spaces, and subtract any empty parts inside them.

Enter the final thickness of topsoil you want to add, not the total existing soil depth. For low spots, use the average fill depth or split them into smaller sections.

Sections and buying options

Section 1

Section name Optional

Include or exclude?

How do you know this section’s size?

Shape

Length and width units

Length

Feet

Inches (0 to less than 12)

Width

Feet

Inches (0 to less than 12)

Decimal feet also work. Depth is entered separately below.

Added topsoil depth / average depth

Use the desired finished layer thickness. Split uneven areas into sections. Settlement compensation is optional below.

Depth units

Identical sections

Use 1 unless you have several sections with exactly these measurements.

Buying options Optional

These settings apply to one material across all sections. Leave them blank when you only need volume.

Expected volume loss after settling

Optional, 0–50%. Ask your supplier. A 20% volume loss means ordering finished volume ÷ 0.8, not just adding 20%. Starts at 0%.

Minimum bulk order

cu yd

Supplier’s minimum purchase quantity, applied before bulk increment rounding. Does not affect bag counts.

Bulk delivery fee (total)

Enter the quoted fee for the whole order, including all loads if applicable. Blank means no fee included.

Extra material allowance

Starts at 0%. Applied after settlement compensation. Use for handling losses or measurement uncertainty; do not count settlement twice.

Bulk ordering increment

cu yd

For example, enter 0.25 if your supplier sells in quarter-yard increments. Leave blank for no rounding.

Topsoil volume per bag

cu ft

Use cu ft or liters printed on the bag. A 40 lb bag has no universal volume; ask the manufacturer if only weight is listed.

Bag volume units

Bulk price per cubic yard

$/cu yd

Price per bag

$/bag

Material density

tons/cu yd

Ask your supplier for the density of this material in the condition being ordered. No generic density is assumed.

Density units

Your result

Know how many yards you need

Enter dimensions, an area and depth, or a known volume. Your measured volume and optional buying estimates will appear here.

Suggest an improvement

Measure the added layer

Separate finished depth from purchasing quantity.

Measure non-overlapping footprints. Enter the desired added depth, using a representative average for uneven fill. Deduct obstacles only once; do not subtract them again if your known area is already net.

Finished volume

Area (sq ft) × added depth (in) ÷ 324 = cubic yards. Circle area uses diameter; triangle area uses base and perpendicular height.

Loose soil target

Finished volume ÷ (1 − settling loss ÷ 100), then multiply by (1 + extra allowance ÷ 100). Ask your supplier for a settling estimate.

Bulk order

Use the larger of the loose soil target and the supplier’s minimum. Round up to the entered ordering increment. Delivery cost is a quoted total, not calculated per truck.

Whole bags

Round up loose soil target ÷ labeled bag volume. Bulk minimums and rounding do not change bag counts. Weight-only bags need a volume specification.

Compare material quantities before ordering

The example above needs 1.375 cu yd after settling and allowance. With a 2 cu yd minimum and 0.5 cu yd increments, buy 2 bulk cu yd. At $40/cu yd plus $60 delivery, that is $140. Alternatively, 0.75 cu ft bags require 50 bags; at $3 each, bagged material is $150 before delivery and tax. All prices are illustrative.

FAQ

Topsoil planning questions

How much topsoil do I need?

For a rectangular area, multiply length (ft) × width (ft) × added depth (in) ÷ 324 to get cubic yards. For an already measured area, use area (sq ft) × depth (in) ÷ 324. A 12 × 9 ft area with 3 inches of added soil needs 1 cubic yard before adjustments.

What depth should I enter?

Enter only the thickness of new topsoil you want to add, not the total existing soil profile. Lawn topdressing, new lawn preparation, and filling a low spot need different depths. Choose depth based on site conditions and local gardening guidance. A target depth is not a soil-quality or drainage recommendation.

How do I allow for settling?

If your supplier expects loose soil to lose 20% of its volume, divide the finished volume by 0.8. One finished cubic yard requires 1.25 loose cubic yards. This is different from adding 20%. The default is 0%; no universal settling rate is assumed. Ordinary extra allowance is applied afterward.

How many 40 lb bags do I need?

Bag weight alone cannot determine volume. Moisture, composition, and density vary. Enter the volume printed on the bag in cubic feet, cubic yards, or liters. For 0.75 cu ft bags, one cubic yard requires 36 bags before adjustments.

How do I fill uneven areas?

Split low spots into smaller sections and use their average added depth. Use separate rows for different depths and quantities. Excluded sections represent spaces that will not receive soil. This is a volume estimate, not a slope, grading, or drainage design.

What is included in bulk and bag estimates?

Both use the loose-soil target after settlement compensation and extra allowance. Bulk orders also respect your supplier’s minimum quantity and ordering increment. Bags round up independently. Bulk cost adds your quoted total delivery fee; bag cost covers material only. Tax, spreading labor, equipment, and other fees are excluded.

Can I estimate tons or truck loads?

Enter supplier-provided density in the condition being delivered to estimate US short tons, pounds, and kilograms. No default topsoil density is assumed. Truck capacity, payload limits, access, and delivery restrictions must be confirmed with the supplier; this calculator does not determine a safe vehicle load.

Is topsoil the same as raised bed mix?

No single blend suits every project. Check soil quality and amendments for your intended plants. Use the Raised Bed Soil Calculator for inside bed dimensions and fill depth; this tool is for estimating an added topsoil layer or fill volume.

References

Check the soil and the supplier’s specifications.

Home Depot mulch and topsoil calculator

Use measured dimensions or existing area with depth, and the volume of your chosen bag.

View volume calculator ↗

University of Maryland Extension

Check site conditions and soil quality before establishing a lawn or adding soil to low spots.

View lawn preparation guidance ↗

University of Minnesota Extension

Soil testing helps assess amendments needed for lawns and gardens.

View soil testing guidance ↗